21965255 has 16 divisors (see below), whose sum is σ = 28557984. Its totient is φ = 16122240.

The previous prime is 21965249. The next prime is 21965351. The reversal of 21965255 is 55256912.

It is not a de Polignac number, because 21965255 - 2¹⁰ = 21964231 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10832 + ... + 12698.

It is an arithmetic number, because the mean of its divisors is an integer number (1784874).

Almost surely, 2^21965255 is an apocalyptic number.

21965255 is a deficient number, since it is larger than the sum of its proper divisors (6592729).

21965255 is a wasteful number, since it uses less digits than its factorization.

21965255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2066.

The product of its digits is 27000, while the sum is 35.

The square root of 21965255 is about 4686.7104668413. The cubic root of 21965255 is about 280.0563449534.

The spelling of 21965255 in words is "twenty-one million, nine hundred sixty-five thousand, two hundred fifty-five".