78620731 has 16 divisors (see below), whose sum is σ = 91869120. Its totient is φ = 65894400.

The previous prime is 78620701. The next prime is 78620749. The reversal of 78620731 is 13702687.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78620731 is a prime.

It is a super-2 number, since 2×78620731² = 12362438685948722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78620701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59781 + ... + 61081.

It is an arithmetic number, because the mean of its divisors is an integer number (5741820).

Almost surely, 2^78620731 is an apocalyptic number.

78620731 is a deficient number, since it is larger than the sum of its proper divisors (13248389).

78620731 is a wasteful number, since it uses less digits than its factorization.

78620731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 78620731 is about 8866.8332001905. The cubic root of 78620731 is about 428.3962815159.

The spelling of 78620731 in words is "seventy-eight million, six hundred twenty thousand, seven hundred thirty-one".