78157073 has 2 divisors, whose sum is σ = 78157074. Its totient is φ = 78157072.

The previous prime is 78157049. The next prime is 78157091. The reversal of 78157073 is 37075187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63234304 + 14922769 = 7952^2 + 3863^2 .

It is a cyclic number.

It is not a de Polignac number, because 78157073 - 2²² = 73962769 is a prime.

It is a super-2 number, since 2×78157073² = 12217056119854658, which contains 22 as substring.

It is equal to p_4568195 and since 78157073 and 4568195 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (78157873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39078536 + 39078537.

It is an arithmetic number, because the mean of its divisors is an integer number (39078537).

Almost surely, 2^78157073 is an apocalyptic number.

It is an amenable number.

78157073 is a deficient number, since it is larger than the sum of its proper divisors (1).

78157073 is an equidigital number, since it uses as much as digits as its factorization.

78157073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41160, while the sum is 38.

The square root of 78157073 is about 8840.6489015230. The cubic root of 78157073 is about 427.5524789946.

The spelling of 78157073 in words is "seventy-eight million, one hundred fifty-seven thousand, seventy-three".