21251300136544 has 12 divisors (see below), whose sum is σ = 41838497143884. Its totient is φ = 10625650068256.

The previous prime is 21251300136503. The next prime is 21251300136613. The reversal of 21251300136544 is 44563100315212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332051564602 + ... + 332051564665.

It is an arithmetic number, because the mean of its divisors is an integer number (3486541428657).

Almost surely, 2^{21251300136544} is an apocalyptic number.

It is an amenable number.

21251300136544 is a deficient number, since it is larger than the sum of its proper divisors (20587197007340).

21251300136544 is an equidigital number, since it uses as much as digits as its factorization.

21251300136544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664103129277 (or 664103129269 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 21251300136544 in words is "twenty-one trillion, two hundred fifty-one billion, three hundred million, one hundred thirty-six thousand, five hundred forty-four".