21395262139 has 16 divisors (see below), whose sum is σ = 21731807232. Its totient is φ = 21061853568.

The previous prime is 21395262107. The next prime is 21395262199. The reversal of 21395262139 is 93126259312.

It is a cyclic number.

It is not a de Polignac number, because 21395262139 - 2⁵ = 21395262107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21395262095 and 21395262104.

It is not an unprimeable number, because it can be changed into a prime (21395262199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11735382 + ... + 11737204.

It is an arithmetic number, because the mean of its divisors is an integer number (1358237952).

Almost surely, 2^21395262139 is an apocalyptic number.

21395262139 is a deficient number, since it is larger than the sum of its proper divisors (336545093).

21395262139 is a wasteful number, since it uses less digits than its factorization.

21395262139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2586.

The product of its digits is 174960, while the sum is 43.

The spelling of 21395262139 in words is "twenty-one billion, three hundred ninety-five million, two hundred sixty-two thousand, one hundred thirty-nine".