78698731 has 2 divisors, whose sum is σ = 78698732. Its totient is φ = 78698730.

The previous prime is 78698689. The next prime is 78698749. The reversal of 78698731 is 13789687.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78698731 is a prime.

It is a super-2 number, since 2×78698731² = 12386980522020722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78698771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39349365 + 39349366.

It is an arithmetic number, because the mean of its divisors is an integer number (39349366).

Almost surely, 2^78698731 is an apocalyptic number.

78698731 is a deficient number, since it is larger than the sum of its proper divisors (1).

78698731 is an equidigital number, since it uses as much as digits as its factorization.

78698731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 49.

The square root of 78698731 is about 8871.2305234392. The cubic root of 78698731 is about 428.5379060182.

The spelling of 78698731 in words is "seventy-eight million, six hundred ninety-eight thousand, seven hundred thirty-one".