21065251239 has 12 divisors (see below), whose sum is σ = 30439281600. Its totient is φ = 14038102464.

The previous prime is 21065251237. The next prime is 21065251241. The reversal of 21065251239 is 93215256012.

It is a happy number.

21065251239 is a `hidden beast` number, since 2 + 1 + 0 + 6 + 525 + 123 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (21065251237) and next prime (21065251241).

It is not a de Polignac number, because 21065251239 - 2¹ = 21065251237 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21065251231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 425079 + ... + 472040.

It is an arithmetic number, because the mean of its divisors is an integer number (2536606800).

Almost surely, 2^21065251239 is an apocalyptic number.

21065251239 is a deficient number, since it is larger than the sum of its proper divisors (9374030361).

21065251239 is a wasteful number, since it uses less digits than its factorization.

21065251239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 899734 (or 899731 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 21065251239 in words is "twenty-one billion, sixty-five million, two hundred fifty-one thousand, two hundred thirty-nine".