1215263640 has 32 divisors (see below), whose sum is σ = 3645791280. Its totient is φ = 324070272.

The previous prime is 1215263639. The next prime is 1215263641. The reversal of 1215263640 is 463625121.

1215263640 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1215263639) and next prime (1215263641).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1215263598 and 1215263607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215263641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5063479 + ... + 5063718.

Almost surely, 2^1215263640 is an apocalyptic number.

1215263640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1215263640 is an abundant number, since it is smaller than the sum of its proper divisors (2430527640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1215263640 is a wasteful number, since it uses less digits than its factorization.

1215263640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10127211 (or 10127207 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 1215263640 is about 34860.6316638124. The cubic root of 1215263640 is about 1067.1451659588.

Adding to 1215263640 its reverse (463625121), we get a palindrome (1678888761).

The spelling of 1215263640 in words is "one billion, two hundred fifteen million, two hundred sixty-three thousand, six hundred forty".