81924619 has 12 divisors (see below), whose sum is σ = 97330464. Its totient is φ = 68725104.

The previous prime is 81924607. The next prime is 81924653. The reversal of 81924619 is 91642918.

It is not a de Polignac number, because 81924619 - 2⁵ = 81924587 is a prime.

It is a super-2 number, since 2×81924619² = 13423286396590322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81924119) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15484 + ... + 20089.

It is an arithmetic number, because the mean of its divisors is an integer number (8110872).

Almost surely, 2^81924619 is an apocalyptic number.

81924619 is a deficient number, since it is larger than the sum of its proper divisors (15405845).

81924619 is a wasteful number, since it uses less digits than its factorization.

81924619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35634 (or 35627 counting only the distinct ones).

The product of its digits is 31104, while the sum is 40.

The square root of 81924619 is about 9051.2219617022. The cubic root of 81924619 is about 434.3149811938.

The spelling of 81924619 in words is "eighty-one million, nine hundred twenty-four thousand, six hundred nineteen".