81977413 has 8 divisors (see below), whose sum is σ = 94165632. Its totient is φ = 69908496.

The previous prime is 81977411. The next prime is 81977429. The reversal of 81977413 is 31477918.

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

It is not a de Polignac number, because 81977413 - 2¹ = 81977411 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81977411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28345 + ... + 31102.

It is an arithmetic number, because the mean of its divisors is an integer number (11770704).

Almost surely, 2^81977413 is an apocalyptic number.

It is an amenable number.

81977413 is a deficient number, since it is larger than the sum of its proper divisors (12188219).

81977413 is a wasteful number, since it uses less digits than its factorization.

81977413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59651.

The product of its digits is 42336, while the sum is 40.

The square root of 81977413 is about 9054.1378938030. The cubic root of 81977413 is about 434.4082551563.

The spelling of 81977413 in words is "eighty-one million, nine hundred seventy-seven thousand, four hundred thirteen".