78765251 has 2 divisors, whose sum is σ = 78765252. Its totient is φ = 78765250.

The previous prime is 78765221. The next prime is 78765259. The reversal of 78765251 is 15256787.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78765251 - 2⁶ = 78765187 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78765199 and 78765208.

It is not a weakly prime, because it can be changed into another prime (78765259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39382625 + 39382626.

It is an arithmetic number, because the mean of its divisors is an integer number (39382626).

Almost surely, 2^78765251 is an apocalyptic number.

78765251 is a deficient number, since it is larger than the sum of its proper divisors (1).

78765251 is an equidigital number, since it uses as much as digits as its factorization.

78765251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 117600, while the sum is 41.

The square root of 78765251 is about 8874.9789295525. The cubic root of 78765251 is about 428.6586123848.

The spelling of 78765251 in words is "seventy-eight million, seven hundred sixty-five thousand, two hundred fifty-one".