81979077 has 8 divisors (see below), whose sum is σ = 109347264. Its totient is φ = 54631808.

The previous prime is 81979043. The next prime is 81979081. The reversal of 81979077 is 77097918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81979077 - 2¹⁰ = 81978053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81979477) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12808 + ... + 18110.

It is an arithmetic number, because the mean of its divisors is an integer number (13668408).

Almost surely, 2^81979077 is an apocalyptic number.

It is an amenable number.

81979077 is a deficient number, since it is larger than the sum of its proper divisors (27368187).

81979077 is a wasteful number, since it uses less digits than its factorization.

81979077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10459.

The product of its (nonzero) digits is 222264, while the sum is 48.

The square root of 81979077 is about 9054.2297850231. The cubic root of 81979077 is about 434.4111943824.

The spelling of 81979077 in words is "eighty-one million, nine hundred seventy-nine thousand, seventy-seven".