213688786 has 4 divisors (see below), whose sum is σ = 320533182. Its totient is φ = 106844392.

The previous prime is 213688777. The next prime is 213688799. The reversal of 213688786 is 687886312.

213688786 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 129618225 + 84070561 = 11385^2 + 9169^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53422195 + ... + 53422198.

Almost surely, 2^213688786 is an apocalyptic number.

213688786 is a deficient number, since it is larger than the sum of its proper divisors (106844396).

213688786 is a wasteful number, since it uses less digits than its factorization.

213688786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106844395.

The product of its digits is 774144, while the sum is 49.

The square root of 213688786 is about 14618.0978926808. The cubic root of 213688786 is about 597.8523085789.

The spelling of 213688786 in words is "two hundred thirteen million, six hundred eighty-eight thousand, seven hundred eighty-six".