21155274 has 24 divisors (see below), whose sum is σ = 52384800. Its totient is φ = 6044328.

The previous prime is 21155263. The next prime is 21155287. The reversal of 21155274 is 47255112.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83824 + ... + 84075.

It is an arithmetic number, because the mean of its divisors is an integer number (2182700).

Almost surely, 2^21155274 is an apocalyptic number.

21155274 is an abundant number, since it is smaller than the sum of its proper divisors (31229526).

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

21155274 is a wasteful number, since it uses less digits than its factorization.

21155274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167914 (or 167911 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 21155274 is about 4599.4862756617. The cubic root of 21155274 is about 276.5707314030.

The spelling of 21155274 in words is "twenty-one million, one hundred fifty-five thousand, two hundred seventy-four".