81220774 has 16 divisors (see below), whose sum is σ = 127409760. Its totient is φ = 38758720.

The previous prime is 81220759. The next prime is 81220787. The reversal of 81220774 is 47702218.

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, 22272 + ... + 25660.

It is an arithmetic number, because the mean of its divisors is an integer number (7963110).

Almost surely, 2^81220774 is an apocalyptic number.

81220774 is a deficient number, since it is larger than the sum of its proper divisors (46188986).

81220774 is a wasteful number, since it uses less digits than its factorization.

81220774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3935.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 81220774 is about 9012.2568760550. The cubic root of 81220774 is about 433.0676147418.

The spelling of 81220774 in words is "eighty-one million, two hundred twenty thousand, seven hundred seventy-four".