21895655 has 16 divisors (see below), whose sum is σ = 28007424. Its totient is φ = 16394400.

The previous prime is 21895651. The next prime is 21895661. The reversal of 21895655 is 55659812.

It is not a de Polignac number, because 21895655 - 2² = 21895651 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21895651) 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, 3380 + ... + 7430.

It is an arithmetic number, because the mean of its divisors is an integer number (1750464).

Almost surely, 2^21895655 is an apocalyptic number.

21895655 is a deficient number, since it is larger than the sum of its proper divisors (6111769).

21895655 is a wasteful number, since it uses less digits than its factorization.

21895655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4126.

The product of its digits is 108000, while the sum is 41.

The square root of 21895655 is about 4679.2793248533. The cubic root of 21895655 is about 279.7602326682.

The spelling of 21895655 in words is "twenty-one million, eight hundred ninety-five thousand, six hundred fifty-five".