72778687 has 4 divisors (see below), whose sum is σ = 72957040. Its totient is φ = 72600336.

The previous prime is 72778679. The next prime is 72778709. The reversal of 72778687 is 78687727.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72778687 - 2³ = 72778679 is a prime.

It is a Duffinian number.

It is a zygodrome in base 6.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72778637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88563 + ... + 89380.

It is an arithmetic number, because the mean of its divisors is an integer number (18239260).

Almost surely, 2^72778687 is an apocalyptic number.

72778687 is a deficient number, since it is larger than the sum of its proper divisors (178353).

72778687 is a wasteful number, since it uses less digits than its factorization.

72778687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178352.

The product of its digits is 1843968, while the sum is 52.

The square root of 72778687 is about 8531.0425505913. The cubic root of 72778687 is about 417.5111441203.

The spelling of 72778687 in words is "seventy-two million, seven hundred seventy-eight thousand, six hundred eighty-seven".