81477879 has 16 divisors (see below), whose sum is σ = 126263040. Its totient is φ = 45768960.

The previous prime is 81477839. The next prime is 81477881. The reversal of 81477879 is 97877418.

It is not a de Polignac number, because 81477879 - 2⁸ = 81477623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81477839) 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, 31642 + ... + 34119.

It is an arithmetic number, because the mean of its divisors is an integer number (7891440).

Almost surely, 2^81477879 is an apocalyptic number.

81477879 is a deficient number, since it is larger than the sum of its proper divisors (44785161).

81477879 is a wasteful number, since it uses less digits than its factorization.

81477879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65830.

The product of its digits is 790272, while the sum is 51.

The square root of 81477879 is about 9026.5097906112. The cubic root of 81477879 is about 433.5240930670.

The spelling of 81477879 in words is "eighty-one million, four hundred seventy-seven thousand, eight hundred seventy-nine".