213118978 has 4 divisors (see below), whose sum is σ = 319678470. Its totient is φ = 106559488.

The previous prime is 213118963. The next prime is 213119063. The reversal of 213118978 is 879811312.

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., 137898049 + 75220929 = 11743^2 + 8673^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 213118978.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53279743 + ... + 53279746.

Almost surely, 2^213118978 is an apocalyptic number.

213118978 is a deficient number, since it is larger than the sum of its proper divisors (106559492).

213118978 is a wasteful number, since it uses less digits than its factorization.

213118978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106559491.

The product of its digits is 24192, while the sum is 40.

The square root of 213118978 is about 14598.5950693894. The cubic root of 213118978 is about 597.3204380980.

The spelling of 213118978 in words is "two hundred thirteen million, one hundred eighteen thousand, nine hundred seventy-eight".