21077613125 has 20 divisors (see below), whose sum is σ = 26981022684. Its totient is φ = 16450800000.

The previous prime is 21077613119. The next prime is 21077613127. The reversal of 21077613125 is 52131677012.

It can be written as a sum of positive squares in 10 ways, for example, as 20150654209 + 926958916 = 141953^2 + 30446^2 .

It is not a de Polignac number, because 21077613125 - 2¹⁸ = 21077350981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21077613127) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 385646 + ... + 436895.

Almost surely, 2^21077613125 is an apocalyptic number.

21077613125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21077613125 is a deficient number, since it is larger than the sum of its proper divisors (5903409559).

21077613125 is an frugal number, since it uses more digits than its factorization.

21077613125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822602 (or 822587 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 35.

The spelling of 21077613125 in words is "twenty-one billion, seventy-seven million, six hundred thirteen thousand, one hundred twenty-five".