21077127125 has 16 divisors (see below), whose sum is σ = 26330481840. Its totient is φ = 16844889600.

The previous prime is 21077127107. The next prime is 21077127217. The reversal of 21077127125 is 52172177012.

It can be written as a sum of positive squares in 8 ways, for example, as 10631878321 + 10445248804 = 103111^2 + 102202^2 .

It is not a de Polignac number, because 21077127125 - 2⁶ = 21077127061 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42569 + ... + 209681.

It is an arithmetic number, because the mean of its divisors is an integer number (1645655115).

Almost surely, 2^21077127125 is an apocalyptic number.

21077127125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21077127125 is a deficient number, since it is larger than the sum of its proper divisors (5253354715).

21077127125 is a wasteful number, since it uses less digits than its factorization.

21077127125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168137 (or 168127 counting only the distinct ones).

The product of its (nonzero) digits is 13720, while the sum is 35.

The spelling of 21077127125 in words is "twenty-one billion, seventy-seven million, one hundred twenty-seven thousand, one hundred twenty-five".