21040400013 has 16 divisors (see below), whose sum is σ = 29707166016. Its totient is φ = 13200454400.

The previous prime is 21040400009. The next prime is 21040400039. The reversal of 21040400013 is 31000404012.

It is a cyclic number.

It is not a de Polignac number, because 21040400013 - 2² = 21040400009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21040399965 and 21040400001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21040400053) 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, 741538 + ... + 769388.

It is an arithmetic number, because the mean of its divisors is an integer number (1856697876).

Almost surely, 2^21040400013 is an apocalyptic number.

It is an amenable number.

21040400013 is a deficient number, since it is larger than the sum of its proper divisors (8666766003).

21040400013 is a wasteful number, since it uses less digits than its factorization.

21040400013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42684.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21040400013 its reverse (31000404012), we get a palindrome (52040804025).

The spelling of 21040400013 in words is "twenty-one billion, forty million, four hundred thousand, thirteen".