21310011537 has 16 divisors (see below), whose sum is σ = 29599004160. Its totient is φ = 13622256000.

The previous prime is 21310011493. The next prime is 21310011553. The reversal of 21310011537 is 73511001312.

It is a happy number.

It is not a de Polignac number, because 21310011537 - 2¹⁴ = 21309995153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21310011587) 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, 1040964 + ... + 1061237.

It is an arithmetic number, because the mean of its divisors is an integer number (1849937760).

Almost surely, 2^21310011537 is an apocalyptic number.

It is an amenable number.

21310011537 is a deficient number, since it is larger than the sum of its proper divisors (8288992623).

21310011537 is a wasteful number, since it uses less digits than its factorization.

21310011537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102344.

The product of its (nonzero) digits is 630, while the sum is 24.

Adding to 21310011537 its reverse (73511001312), we get a palindrome (94821012849).

The spelling of 21310011537 in words is "twenty-one billion, three hundred ten million, eleven thousand, five hundred thirty-seven".