21155262 has 32 divisors (see below), whose sum is σ = 45239040. Its totient is φ = 6578880.

The previous prime is 21155261. The next prime is 21155263. The reversal of 21155262 is 26255112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21155261) and next prime (21155263).

It is a super-2 number, since 2×21155262² = 895090220577288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155261) 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, 3789 + ... + 7527.

It is an arithmetic number, because the mean of its divisors is an integer number (1413720).

Almost surely, 2^21155262 is an apocalyptic number.

21155262 is an abundant number, since it is smaller than the sum of its proper divisors (24083778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21155262 is a wasteful number, since it uses less digits than its factorization.

21155262 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3808.

The product of its digits is 1200, while the sum is 24.

The square root of 21155262 is about 4599.4849711680. The cubic root of 21155262 is about 276.5706791095.

The spelling of 21155262 in words is "twenty-one million, one hundred fifty-five thousand, two hundred sixty-two".