81698424 has 32 divisors (see below), whose sum is σ = 204491520. Its totient is φ = 27200096.

The previous prime is 81698359. The next prime is 81698429. The reversal of 81698424 is 42489618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81698429) 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, 26449 + ... + 29375.

It is an arithmetic number, because the mean of its divisors is an integer number (6390360).

Almost surely, 2^81698424 is an apocalyptic number.

It is an amenable number.

81698424 is an abundant number, since it is smaller than the sum of its proper divisors (122793096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81698424 is a wasteful number, since it uses less digits than its factorization.

81698424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4099 (or 4095 counting only the distinct ones).

The product of its digits is 110592, while the sum is 42.

The square root of 81698424 is about 9038.7180506972. The cubic root of 81698424 is about 433.9148962084.

The spelling of 81698424 in words is "eighty-one million, six hundred ninety-eight thousand, four hundred twenty-four".