78193857 has 24 divisors (see below), whose sum is σ = 121903392. Its totient is φ = 44452800.

The previous prime is 78193849. The next prime is 78193861. The reversal of 78193857 is 75839187.

It is not a de Polignac number, because 78193857 - 2³ = 78193849 is a prime.

It is a super-2 number, since 2×78193857² = 12228558545072898, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78193807) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29757 + ... + 32277.

It is an arithmetic number, because the mean of its divisors is an integer number (5079308).

Almost surely, 2^78193857 is an apocalyptic number.

It is an amenable number.

78193857 is a deficient number, since it is larger than the sum of its proper divisors (43709535).

78193857 is a wasteful number, since it uses less digits than its factorization.

78193857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2749 (or 2742 counting only the distinct ones).

The product of its digits is 423360, while the sum is 48.

The square root of 78193857 is about 8842.7290470759. The cubic root of 78193857 is about 427.6195431905.

The spelling of 78193857 in words is "seventy-eight million, one hundred ninety-three thousand, eight hundred fifty-seven".