72100778 has 4 divisors (see below), whose sum is σ = 108151170. Its totient is φ = 36050388.

The previous prime is 72100739. The next prime is 72100783. The reversal of 72100778 is 87700127.

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., 66961489 + 5139289 = 8183^2 + 2267^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18025193 + ... + 18025196.

Almost surely, 2^72100778 is an apocalyptic number.

72100778 is a deficient number, since it is larger than the sum of its proper divisors (36050392).

72100778 is a wasteful number, since it uses less digits than its factorization.

72100778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36050391.

The product of its (nonzero) digits is 5488, while the sum is 32.

The square root of 72100778 is about 8491.2176983045. The cubic root of 72100778 is about 416.2107729058.

The spelling of 72100778 in words is "seventy-two million, one hundred thousand, seven hundred seventy-eight".