78124991 has 8 divisors (see below), whose sum is σ = 92166144. Its totient is φ = 64803960.

The previous prime is 78124973. The next prime is 78124999. The reversal of 78124991 is 19942187.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78124991 - 2¹⁰ = 78123967 is a prime.

It is a super-2 number, since 2×78124991² = 12207028437500162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78124999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179795 + ... + 180228.

It is an arithmetic number, because the mean of its divisors is an integer number (11520768).

Almost surely, 2^78124991 is an apocalyptic number.

78124991 is a deficient number, since it is larger than the sum of its proper divisors (14041153).

78124991 is a wasteful number, since it uses less digits than its factorization.

78124991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360061.

The product of its digits is 36288, while the sum is 41.

The square root of 78124991 is about 8838.8342557149. The cubic root of 78124991 is about 427.4939702534.

The spelling of 78124991 in words is "seventy-eight million, one hundred twenty-four thousand, nine hundred ninety-one".