72578728069226 has 4 divisors (see below), whose sum is σ = 108868092103842. Its totient is φ = 36289364034612.

The previous prime is 72578728069213. The next prime is 72578728069231. The reversal of 72578728069226 is 62296082787527.

It is a happy number.

It is a Cunningham number, because it is equal to 8519315²+1.

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., 72578728069225 + 1 = 8519315^2 + 1^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 72578728069226.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18144682017305 + ... + 18144682017308.

Almost surely, 2^{72578728069226} is an apocalyptic number.

72578728069226 is a deficient number, since it is larger than the sum of its proper divisors (36289364034616).

72578728069226 is a wasteful number, since it uses less digits than its factorization.

72578728069226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36289364034615.

The product of its (nonzero) digits is 568995840, while the sum is 71.

The spelling of 72578728069226 in words is "seventy-two trillion, five hundred seventy-eight billion, seven hundred twenty-eight million, sixty-nine thousand, two hundred twenty-six".