81361776 has 40 divisors (see below), whose sum is σ = 211494400. Its totient is φ = 26951616.

The previous prime is 81361751. The next prime is 81361789. The reversal of 81361776 is 67716318.

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, 2625 + ... + 13023.

It is an arithmetic number, because the mean of its divisors is an integer number (5287360).

Almost surely, 2^81361776 is an apocalyptic number.

It is an amenable number.

81361776 is an abundant number, since it is smaller than the sum of its proper divisors (130132624).

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

81361776 is a wasteful number, since it uses less digits than its factorization.

81361776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10573 (or 10567 counting only the distinct ones).

The product of its digits is 42336, while the sum is 39.

The square root of 81361776 is about 9020.0762746221. The cubic root of 81361776 is about 433.3180765174.

The spelling of 81361776 in words is "eighty-one million, three hundred sixty-one thousand, seven hundred seventy-six".