78715477 has 2 divisors, whose sum is σ = 78715478. Its totient is φ = 78715476.

The previous prime is 78715451. The next prime is 78715501. The reversal of 78715477 is 77451787.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78251716 + 463761 = 8846^2 + 681^2 .

It is a cyclic number.

It is not a de Polignac number, because 78715477 - 2⁷ = 78715349 is a prime.

It is a super-2 number, since 2×78715477² = 12392252638675058, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78715447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39357738 + 39357739.

It is an arithmetic number, because the mean of its divisors is an integer number (39357739).

Almost surely, 2^78715477 is an apocalyptic number.

It is an amenable number.

78715477 is a deficient number, since it is larger than the sum of its proper divisors (1).

78715477 is an equidigital number, since it uses as much as digits as its factorization.

78715477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384160, while the sum is 46.

The square root of 78715477 is about 8872.1743107313. The cubic root of 78715477 is about 428.5682995063.

The spelling of 78715477 in words is "seventy-eight million, seven hundred fifteen thousand, four hundred seventy-seven".