78620091 has 16 divisors (see below), whose sum is σ = 114516480. Its totient is φ = 47581920.

The previous prime is 78620029. The next prime is 78620099. The reversal of 78620091 is 19002687.

It is not a de Polignac number, because 78620091 - 2¹⁵ = 78587323 is a prime.

It is a super-2 number, since 2×78620091² = 12362237417696562, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (78620099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33141 + ... + 35433.

It is an arithmetic number, because the mean of its divisors is an integer number (7157280).

Almost surely, 2^78620091 is an apocalyptic number.

78620091 is a deficient number, since it is larger than the sum of its proper divisors (35896389).

78620091 is a wasteful number, since it uses less digits than its factorization.

78620091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3346.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 78620091 is about 8866.7971105693. The cubic root of 78620091 is about 428.3951190814.

The spelling of 78620091 in words is "seventy-eight million, six hundred twenty thousand, ninety-one".