21156095 has 4 divisors (see below), whose sum is σ = 25387320. Its totient is φ = 16924872.

The previous prime is 21156077. The next prime is 21156127. The reversal of 21156095 is 59065112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21156095 - 2⁸ = 21155839 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2115605 + ... + 2115614.

It is an arithmetic number, because the mean of its divisors is an integer number (6346830).

Almost surely, 2^21156095 is an apocalyptic number.

21156095 is a deficient number, since it is larger than the sum of its proper divisors (4231225).

21156095 is an equidigital number, since it uses as much as digits as its factorization.

21156095 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4231224.

The product of its (nonzero) digits is 2700, while the sum is 29.

The square root of 21156095 is about 4599.5755238935. The cubic root of 21156095 is about 276.5743091024.

The spelling of 21156095 in words is "twenty-one million, one hundred fifty-six thousand, ninety-five".