78290791 has 2 divisors, whose sum is σ = 78290792. Its totient is φ = 78290790.

The previous prime is 78290761. The next prime is 78290803. The reversal of 78290791 is 19709287.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78290791 - 2¹⁹ = 77766503 is a prime.

It is a super-2 number, since 2×78290791² = 12258895910811362, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78290731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39145395 + 39145396.

It is an arithmetic number, because the mean of its divisors is an integer number (39145396).

Almost surely, 2^78290791 is an apocalyptic number.

78290791 is a deficient number, since it is larger than the sum of its proper divisors (1).

78290791 is an equidigital number, since it uses as much as digits as its factorization.

78290791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63504, while the sum is 43.

The square root of 78290791 is about 8848.2083497169. The cubic root of 78290791 is about 427.7961715422.

The spelling of 78290791 in words is "seventy-eight million, two hundred ninety thousand, seven hundred ninety-one".