78773531 has 2 divisors, whose sum is σ = 78773532. Its totient is φ = 78773530.

The previous prime is 78773503. The next prime is 78773561. The reversal of 78773531 is 13537787.

It is a weak prime.

It is an emirp because it is prime and its reverse (13537787) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78773531 is a prime.

It is a super-2 number, since 2×78773531² = 12410538372415922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78773561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39386765 + 39386766.

It is an arithmetic number, because the mean of its divisors is an integer number (39386766).

Almost surely, 2^78773531 is an apocalyptic number.

78773531 is a deficient number, since it is larger than the sum of its proper divisors (1).

78773531 is an equidigital number, since it uses as much as digits as its factorization.

78773531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 123480, while the sum is 41.

The square root of 78773531 is about 8875.4453972744. The cubic root of 78773531 is about 428.6736324133.

The spelling of 78773531 in words is "seventy-eight million, seven hundred seventy-three thousand, five hundred thirty-one".