78157049 has 2 divisors, whose sum is σ = 78157050. Its totient is φ = 78157048.

The previous prime is 78157031. The next prime is 78157073. The reversal of 78157049 is 94075187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78145600 + 11449 = 8840^2 + 107^2 .

It is an emirp because it is prime and its reverse (94075187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78157049 - 2¹⁶ = 78091513 is a prime.

It is a super-2 number, since 2×78157049² = 12217048616776802, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78156997 and 78157015.

It is not a weakly prime, because it can be changed into another prime (78157249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39078524 + 39078525.

It is an arithmetic number, because the mean of its divisors is an integer number (39078525).

Almost surely, 2^78157049 is an apocalyptic number.

It is an amenable number.

78157049 is a deficient number, since it is larger than the sum of its proper divisors (1).

78157049 is an equidigital number, since it uses as much as digits as its factorization.

78157049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 78157049 is about 8840.6475441565. The cubic root of 78157049 is about 427.5524352312.

The spelling of 78157049 in words is "seventy-eight million, one hundred fifty-seven thousand, forty-nine".