21278361537021 has 8 divisors (see below), whose sum is σ = 28475839302784. Its totient is φ = 14133229064640.

The previous prime is 21278361536981. The next prime is 21278361537031. The reversal of 21278361537021 is 12073516387212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21278361537021 - 2²² = 21278357342717 is a prime.

It is a Duffinian number.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13086322396 + ... + 13086324021.

It is an arithmetic number, because the mean of its divisors is an integer number (3559479912848).

Almost surely, 2^{21278361537021} is an apocalyptic number.

It is an amenable number.

21278361537021 is a deficient number, since it is larger than the sum of its proper divisors (7197477765763).

21278361537021 is a wasteful number, since it uses less digits than its factorization.

21278361537021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26172646691.

The product of its (nonzero) digits is 846720, while the sum is 48.

The spelling of 21278361537021 in words is "twenty-one trillion, two hundred seventy-eight billion, three hundred sixty-one million, five hundred thirty-seven thousand, twenty-one".