72778993 has 8 divisors (see below), whose sum is σ = 83410560. Its totient is φ = 62206080.

The previous prime is 72778961. The next prime is 72778997. The reversal of 72778993 is 39987727.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 72778993 - 2⁵ = 72778961 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72778993.

It is not an unprimeable number, because it can be changed into a prime (72778997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11968 + ... + 16993.

It is an arithmetic number, because the mean of its divisors is an integer number (10426320).

Almost surely, 2^72778993 is an apocalyptic number.

It is an amenable number.

72778993 is a deficient number, since it is larger than the sum of its proper divisors (10631567).

72778993 is a wasteful number, since it uses less digits than its factorization.

72778993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29327.

The product of its digits is 1333584, while the sum is 52.

The square root of 72778993 is about 8531.0604850745. The cubic root of 72778993 is about 417.5117292652.

The spelling of 72778993 in words is "seventy-two million, seven hundred seventy-eight thousand, nine hundred ninety-three".