72721874 has 4 divisors (see below), whose sum is σ = 109082814. Its totient is φ = 36360936.

The previous prime is 72721841. The next prime is 72721897. The reversal of 72721874 is 47812727.

It is a happy number.

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., 39601849 + 33120025 = 6293^2 + 5755^2 .

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18180467 + ... + 18180470.

Almost surely, 2^72721874 is an apocalyptic number.

72721874 is a deficient number, since it is larger than the sum of its proper divisors (36360940).

72721874 is a wasteful number, since it uses less digits than its factorization.

72721874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36360939.

The product of its digits is 43904, while the sum is 38.

The square root of 72721874 is about 8527.7121199065. The cubic root of 72721874 is about 417.4024756971.

The spelling of 72721874 in words is "seventy-two million, seven hundred twenty-one thousand, eight hundred seventy-four".