78950991 has 16 divisors (see below), whose sum is σ = 122104064. Its totient is φ = 44440704.

The previous prime is 78950987. The next prime is 78950999. The reversal of 78950991 is 19905987.

It is not a de Polignac number, because 78950991 - 2² = 78950987 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78950991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78950999) 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, 26650 + ... + 29463.

It is an arithmetic number, because the mean of its divisors is an integer number (7631504).

Almost surely, 2^78950991 is an apocalyptic number.

78950991 is a deficient number, since it is larger than the sum of its proper divisors (43153073).

78950991 is a wasteful number, since it uses less digits than its factorization.

78950991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56190.

The product of its (nonzero) digits is 204120, while the sum is 48.

The square root of 78950991 is about 8885.4370179525. The cubic root of 78950991 is about 428.9952944752.

The spelling of 78950991 in words is "seventy-eight million, nine hundred fifty thousand, nine hundred ninety-one".