81351879 has 16 divisors (see below), whose sum is σ = 124712448. Its totient is φ = 46206432.

The previous prime is 81351847. The next prime is 81351883. The reversal of 81351879 is 97815318.

It is not a de Polignac number, because 81351879 - 2⁵ = 81351847 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81351879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81351899) 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, 8092 + ... + 15105.

It is an arithmetic number, because the mean of its divisors is an integer number (7794528).

Almost surely, 2^81351879 is an apocalyptic number.

81351879 is a deficient number, since it is larger than the sum of its proper divisors (43360569).

81351879 is a wasteful number, since it uses less digits than its factorization.

81351879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23374.

The product of its digits is 60480, while the sum is 42.

The square root of 81351879 is about 9019.5276483860. The cubic root of 81351879 is about 433.3005059287.

The spelling of 81351879 in words is "eighty-one million, three hundred fifty-one thousand, eight hundred seventy-nine".