20290340 has 24 divisors (see below), whose sum is σ = 48697152. Its totient is φ = 6956640.

The previous prime is 20290331. The next prime is 20290349. The reversal of 20290340 is 4309202.

It is an interprime number because it is at equal distance from previous prime (20290331) and next prime (20290349).

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

It is not an unprimeable number, because it can be changed into a prime (20290349) 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, 72326 + ... + 72605.

It is an arithmetic number, because the mean of its divisors is an integer number (2029048).

Almost surely, 2^20290340 is an apocalyptic number.

20290340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20290340 is an abundant number, since it is smaller than the sum of its proper divisors (28406812).

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

20290340 is a wasteful number, since it uses less digits than its factorization.

20290340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144947 (or 144945 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 20290340 is about 4504.4799921856. The cubic root of 20290340 is about 272.7489630560.

Adding to 20290340 its reverse (4309202), we get a palindrome (24599542).

The spelling of 20290340 in words is "twenty million, two hundred ninety thousand, three hundred forty".