20400252015 has 32 divisors (see below), whose sum is σ = 38346771456. Its totient is φ = 9130181760.

The previous prime is 20400251981. The next prime is 20400252023. The reversal of 20400252015 is 51025200402.

It is a happy number.

It is not a de Polignac number, because 20400252015 - 2⁷ = 20400251887 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20400251982 and 20400252000.

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, 4753159 + ... + 4757448.

It is an arithmetic number, because the mean of its divisors is an integer number (1198336608).

Almost surely, 2^20400252015 is an apocalyptic number.

20400252015 is a deficient number, since it is larger than the sum of its proper divisors (17946519441).

20400252015 is a wasteful number, since it uses less digits than its factorization.

20400252015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9510639.

The product of its (nonzero) digits is 800, while the sum is 21.

Adding to 20400252015 its reverse (51025200402), we get a palindrome (71425452417).

The spelling of 20400252015 in words is "twenty billion, four hundred million, two hundred fifty-two thousand, fifteen".