81955064 has 16 divisors (see below), whose sum is σ = 157414320. Its totient is φ = 39977920.

The previous prime is 81955063. The next prime is 81955067. The reversal of 81955064 is 46055918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81955061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124604 + ... + 125259.

It is an arithmetic number, because the mean of its divisors is an integer number (9838395).

Almost surely, 2^81955064 is an apocalyptic number.

It is an amenable number.

81955064 is a deficient number, since it is larger than the sum of its proper divisors (75459256).

81955064 is a wasteful number, since it uses less digits than its factorization.

81955064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249910 (or 249906 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 38.

The square root of 81955064 is about 9052.9036225953. The cubic root of 81955064 is about 434.3687748810.

The spelling of 81955064 in words is "eighty-one million, nine hundred fifty-five thousand, sixty-four".