21278361537051 has 32 divisors (see below), whose sum is σ = 29522978703360. Its totient is φ = 13621106488704.

The previous prime is 21278361537031. The next prime is 21278361537067. The reversal of 21278361537051 is 15073516387212.

It is not a de Polignac number, because 21278361537051 - 2⁷ = 21278361536923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21278361536985 and 21278361537003.

It is not an unprimeable number, because it can be changed into a prime (21278361537031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 176519266 + ... + 176639768.

It is an arithmetic number, because the mean of its divisors is an integer number (922593084480).

Almost surely, 2^{21278361537051} is an apocalyptic number.

21278361537051 is a deficient number, since it is larger than the sum of its proper divisors (8244617166309).

21278361537051 is a wasteful number, since it uses less digits than its factorization.

21278361537051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144235.

The product of its (nonzero) digits is 2116800, while the sum is 51.

The spelling of 21278361537051 in words is "twenty-one trillion, two hundred seventy-eight billion, three hundred sixty-one million, five hundred thirty-seven thousand, fifty-one".