78163281 has 27 divisors (see below), whose sum is σ = 131648283. Its totient is φ = 44558640.

The previous prime is 78163249. The next prime is 78163313. The reversal of 78163281 is 18236187.

The square root of 78163281 is 8841.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (78163249) and next prime (78163313).

It can be written as a sum of positive squares in only one way, i.e., 370881 + 77792400 = 609^2 + 8820^2 .

It is not a de Polignac number, because 78163281 - 2⁵ = 78163249 is a prime.

It is a super-2 number, since 2×78163281² = 12218996993369922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78163231) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 185451 + ... + 185871.

Almost surely, 2^78163281 is an apocalyptic number.

78163281 is the 8841-st square number.

78163281 is the 4421-st centered octagonal number.

It is an amenable number.

78163281 is a deficient number, since it is larger than the sum of its proper divisors (53485002).

78163281 is an equidigital number, since it uses as much as digits as its factorization.

78163281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862 (or 431 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The cubic root of 78163281 is about 427.5637988297.

Multiplying 78163281 by its sum of digits (36), we get a square (2813878116 = 53046²).

The spelling of 78163281 in words is "seventy-eight million, one hundred sixty-three thousand, two hundred eighty-one".