21769155 has 96 divisors (see below), whose sum is σ = 44029440. Its totient is φ = 10264320.

The previous prime is 21769151. The next prime is 21769183. The reversal of 21769155 is 55196712.

It is not a de Polignac number, because 21769155 - 2² = 21769151 is a prime.

It is a super-2 number, since 2×21769155² = 947792218828050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21769151) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 530935 + ... + 530975.

It is an arithmetic number, because the mean of its divisors is an integer number (458640).

Almost surely, 2^21769155 is an apocalyptic number.

21769155 is an abundant number, since it is smaller than the sum of its proper divisors (22260285).

21769155 is a wasteful number, since it uses less digits than its factorization.

21769155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103 (or 91 counting only the distinct ones).

The product of its digits is 18900, while the sum is 36.

The square root of 21769155 is about 4665.7427061509. The cubic root of 21769155 is about 279.2204293377.

The spelling of 21769155 in words is "twenty-one million, seven hundred sixty-nine thousand, one hundred fifty-five".