72778515 has 8 divisors (see below), whose sum is σ = 116445648. Its totient is φ = 38815200.

The previous prime is 72778501. The next prime is 72778553. The reversal of 72778515 is 51587727.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72778515 - 2⁸ = 72778259 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2425936 + ... + 2425965.

It is an arithmetic number, because the mean of its divisors is an integer number (14555706).

Almost surely, 2^72778515 is an apocalyptic number.

72778515 is a deficient number, since it is larger than the sum of its proper divisors (43667133).

72778515 is a wasteful number, since it uses less digits than its factorization.

72778515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4851909.

The product of its digits is 137200, while the sum is 42.

The square root of 72778515 is about 8531.0324697542. The cubic root of 72778515 is about 417.5108152146.

The spelling of 72778515 in words is "seventy-two million, seven hundred seventy-eight thousand, five hundred fifteen".