78057791 has 16 divisors (see below), whose sum is σ = 93823488. Its totient is φ = 63492000.

The previous prime is 78057787. The next prime is 78057797. The reversal of 78057791 is 19775087.

It is a cyclic number.

It is not a de Polignac number, because 78057791 - 2² = 78057787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78057797) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19241 + ... + 22941.

It is an arithmetic number, because the mean of its divisors is an integer number (5863968).

Almost surely, 2^78057791 is an apocalyptic number.

78057791 is a deficient number, since it is larger than the sum of its proper divisors (15765697).

78057791 is a wasteful number, since it uses less digits than its factorization.

78057791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3862.

The product of its (nonzero) digits is 123480, while the sum is 44.

The square root of 78057791 is about 8835.0320316341. The cubic root of 78057791 is about 427.3713640077.

The spelling of 78057791 in words is "seventy-eight million, fifty-seven thousand, seven hundred ninety-one".