21153010520 has 16 divisors (see below), whose sum is σ = 47594273760. Its totient is φ = 8461204192.

The previous prime is 21153010513. The next prime is 21153010537. The reversal of 21153010520 is 2501035112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21153010492 and 21153010501.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264412592 + ... + 264412671.

It is an arithmetic number, because the mean of its divisors is an integer number (2974642110).

Almost surely, 2^21153010520 is an apocalyptic number.

21153010520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21153010520 is an abundant number, since it is smaller than the sum of its proper divisors (26441263240).

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

21153010520 is a wasteful number, since it uses less digits than its factorization.

21153010520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528825274 (or 528825270 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

Adding to 21153010520 its reverse (2501035112), we get a palindrome (23654045632).

The spelling of 21153010520 in words is "twenty-one billion, one hundred fifty-three million, ten thousand, five hundred twenty".