213706404 has 24 divisors (see below), whose sum is σ = 554053920. Its totient is φ = 71235432.

The previous prime is 213706403. The next prime is 213706429. The reversal of 213706404 is 404607312.

213706404 is a `hidden beast` number, since 2 + 13 + 7 + 0 + 640 + 4 = 666.

It is a super-2 number, since 2×213706404² = 91340854221222432, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (213706403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 989274 + ... + 989489.

It is an arithmetic number, because the mean of its divisors is an integer number (23085580).

Almost surely, 2^213706404 is an apocalyptic number.

It is an amenable number.

213706404 is an abundant number, since it is smaller than the sum of its proper divisors (340347516).

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

213706404 is a wasteful number, since it uses less digits than its factorization.

213706404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1978776 (or 1978768 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 213706404 is about 14618.7004894416. The cubic root of 213706404 is about 597.8687385044.

The spelling of 213706404 in words is "two hundred thirteen million, seven hundred six thousand, four hundred four".