21409637951 has 16 divisors (see below), whose sum is σ = 23619302784. Its totient is φ = 19281405024.

The previous prime is 21409637947. The next prime is 21409637957. The reversal of 21409637951 is 15973690412.

It is not a de Polignac number, because 21409637951 - 2² = 21409637947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21409637896 and 21409637905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21409637957) 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, 485900 + ... + 528126.

It is an arithmetic number, because the mean of its divisors is an integer number (1476206424).

Almost surely, 2^21409637951 is an apocalyptic number.

21409637951 is a deficient number, since it is larger than the sum of its proper divisors (2209664833).

21409637951 is a wasteful number, since it uses less digits than its factorization.

21409637951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43190.

The product of its (nonzero) digits is 408240, while the sum is 47.

The spelling of 21409637951 in words is "twenty-one billion, four hundred nine million, six hundred thirty-seven thousand, nine hundred fifty-one".