21126052637 has 4 divisors (see below), whose sum is σ = 21158111040. Its totient is φ = 21093994236.

The previous prime is 21126052631. The next prime is 21126052669. The reversal of 21126052637 is 73625062112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21126052637 - 2²⁸ = 20857617181 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21126052597 and 21126052606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21126052631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16028213 + ... + 16029530.

It is an arithmetic number, because the mean of its divisors is an integer number (5289527760).

Almost surely, 2^21126052637 is an apocalyptic number.

It is an amenable number.

21126052637 is a deficient number, since it is larger than the sum of its proper divisors (32058403).

21126052637 is an equidigital number, since it uses as much as digits as its factorization.

21126052637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32058402.

The product of its (nonzero) digits is 30240, while the sum is 35.

The spelling of 21126052637 in words is "twenty-one billion, one hundred twenty-six million, fifty-two thousand, six hundred thirty-seven".