21404706 has 16 divisors (see below), whose sum is σ = 43854048. Its totient is φ = 6960800.

The previous prime is 21404689. The next prime is 21404729. The reversal of 21404706 is 60740412.

It is a super-2 number, since 2×21404706² = 916322877892872, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43260 + ... + 43751.

It is an arithmetic number, because the mean of its divisors is an integer number (2740878).

Almost surely, 2^21404706 is an apocalyptic number.

21404706 is an abundant number, since it is smaller than the sum of its proper divisors (22449342).

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

21404706 is a wasteful number, since it uses less digits than its factorization.

21404706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87057.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 21404706 is about 4626.5220198330. The cubic root of 21404706 is about 277.6534594753.

The spelling of 21404706 in words is "twenty-one million, four hundred four thousand, seven hundred six".