81319416 has 32 divisors (see below), whose sum is σ = 205752960. Its totient is φ = 26779232.

The previous prime is 81319409. The next prime is 81319423. The reversal of 81319416 is 61491318.

It is an interprime number because it is at equal distance from previous prime (81319409) and next prime (81319423).

It is a super-2 number, since 2×81319416² = 13225694837162112, which contains 22 as substring.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18420 + ... + 22403.

It is an arithmetic number, because the mean of its divisors is an integer number (6429780).

Almost surely, 2^81319416 is an apocalyptic number.

It is an amenable number.

81319416 is an abundant number, since it is smaller than the sum of its proper divisors (124433544).

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

81319416 is a wasteful number, since it uses less digits than its factorization.

81319416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40915 (or 40911 counting only the distinct ones).

The product of its digits is 5184, while the sum is 33.

The square root of 81319416 is about 9017.7278734723. The cubic root of 81319416 is about 433.2428629014.

The spelling of 81319416 in words is "eighty-one million, three hundred nineteen thousand, four hundred sixteen".