81977607 has 24 divisors (see below), whose sum is σ = 122401344. Its totient is φ = 52830144.

The previous prime is 81977579. The next prime is 81977617. The reversal of 81977607 is 70677918.

It is a happy number.

It is not a de Polignac number, because 81977607 - 2¹¹ = 81975559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81977617) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 56898 + ... + 58320.

It is an arithmetic number, because the mean of its divisors is an integer number (5100056).

Almost surely, 2^81977607 is an apocalyptic number.

81977607 is a deficient number, since it is larger than the sum of its proper divisors (40423737).

81977607 is a wasteful number, since it uses less digits than its factorization.

81977607 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1639 (or 1636 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 45.

The square root of 81977607 is about 9054.1486071303. The cubic root of 81977607 is about 434.4085978325.

The spelling of 81977607 in words is "eighty-one million, nine hundred seventy-seven thousand, six hundred seven".