81226916 has 6 divisors (see below), whose sum is σ = 142147110. Its totient is φ = 40613456.

The previous prime is 81226897. The next prime is 81226939. The reversal of 81226916 is 61962218.

It can be written as a sum of positive squares in only one way, i.e., 77440000 + 3786916 = 8800^2 + 1946^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10153361 + ... + 10153368.

It is an arithmetic number, because the mean of its divisors is an integer number (23691185).

Almost surely, 2^81226916 is an apocalyptic number.

It is an amenable number.

81226916 is a deficient number, since it is larger than the sum of its proper divisors (60920194).

81226916 is a wasteful number, since it uses less digits than its factorization.

81226916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20306733 (or 20306731 counting only the distinct ones).

The product of its digits is 10368, while the sum is 35.

The square root of 81226916 is about 9012.5976277653. The cubic root of 81226916 is about 433.0785308089.

The spelling of 81226916 in words is "eighty-one million, two hundred twenty-six thousand, nine hundred sixteen".