83991147 has 32 divisors (see below), whose sum is σ = 121347072. Its totient is φ = 51537024.

The previous prime is 83991143. The next prime is 83991157. The reversal of 83991147 is 74119938.

It is a happy number.

It is not a de Polignac number, because 83991147 - 2² = 83991143 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 83991099 and 83991108.

It is not an unprimeable number, because it can be changed into a prime (83991143) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 426253 + ... + 426449.

It is an arithmetic number, because the mean of its divisors is an integer number (3792096).

Almost surely, 2^83991147 is an apocalyptic number.

83991147 is a deficient number, since it is larger than the sum of its proper divisors (37355925).

83991147 is a wasteful number, since it uses less digits than its factorization.

83991147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427.

The product of its digits is 54432, while the sum is 42.

The square root of 83991147 is about 9164.6684064400. The cubic root of 83991147 is about 437.9365277804.

The spelling of 83991147 in words is "eighty-three million, nine hundred ninety-one thousand, one hundred forty-seven".