21387077425 has 24 divisors (see below), whose sum is σ = 30483781056. Its totient is φ = 14580632640.

The previous prime is 21387077419. The next prime is 21387077429. The reversal of 21387077425 is 52477078312.

It is not a de Polignac number, because 21387077425 - 2⁷ = 21387077297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21387077429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 322939 + ... + 383488.

It is an arithmetic number, because the mean of its divisors is an integer number (1270157544).

Almost surely, 2^21387077425 is an apocalyptic number.

21387077425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21387077425 is a deficient number, since it is larger than the sum of its proper divisors (9096703631).

21387077425 is a wasteful number, since it uses less digits than its factorization.

21387077425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706617 (or 706612 counting only the distinct ones).

The product of its (nonzero) digits is 658560, while the sum is 46.

The spelling of 21387077425 in words is "twenty-one billion, three hundred eighty-seven million, seventy-seven thousand, four hundred twenty-five".