20131256390 has 32 divisors (see below), whose sum is σ = 43592497920. Its totient is φ = 6538873824.

The previous prime is 20131256389. The next prime is 20131256393. The reversal of 20131256390 is 9365213102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131256393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7566812 + ... + 7569471.

It is an arithmetic number, because the mean of its divisors is an integer number (1362265560).

Almost surely, 2^20131256390 is an apocalyptic number.

20131256390 is an abundant number, since it is smaller than the sum of its proper divisors (23461241530).

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

20131256390 is a wasteful number, since it uses less digits than its factorization.

20131256390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15136316.

The product of its (nonzero) digits is 9720, while the sum is 32.

Adding to 20131256390 its reverse (9365213102), we get a palindrome (29496469492).

The spelling of 20131256390 in words is "twenty billion, one hundred thirty-one million, two hundred fifty-six thousand, three hundred ninety".