21611394 has 32 divisors (see below), whose sum is σ = 54887040. Its totient is φ = 6174576.

The previous prime is 21611389. The next prime is 21611411. The reversal of 21611394 is 49311612.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 28209 + ... + 28964.

It is an arithmetic number, because the mean of its divisors is an integer number (1715220).

Almost surely, 2^21611394 is an apocalyptic number.

21611394 is an abundant number, since it is smaller than the sum of its proper divisors (33275646).

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

21611394 is a wasteful number, since it uses less digits than its factorization.

21611394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57191 (or 57185 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 21611394 is about 4648.8056530683. The cubic root of 21611394 is about 278.5442901711.

The spelling of 21611394 in words is "twenty-one million, six hundred eleven thousand, three hundred ninety-four".