20400243415 has 32 divisors (see below), whose sum is σ = 25964075520. Its totient is φ = 15355004544.

The previous prime is 20400243379. The next prime is 20400243427. The reversal of 20400243415 is 51434200402.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20400243415 - 2²⁵ = 20366688983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20400243415.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6755776 + ... + 6758794.

It is an arithmetic number, because the mean of its divisors is an integer number (811377360).

Almost surely, 2^20400243415 is an apocalyptic number.

20400243415 is a deficient number, since it is larger than the sum of its proper divisors (5563832105).

20400243415 is a wasteful number, since it uses less digits than its factorization.

20400243415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3991.

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 20400243415 its reverse (51434200402), we get a palindrome (71834443817).

The spelling of 20400243415 in words is "twenty billion, four hundred million, two hundred forty-three thousand, four hundred fifteen".