81775956 has 12 divisors (see below), whose sum is σ = 190810592. Its totient is φ = 27258648.

The previous prime is 81775951. The next prime is 81775961. The reversal of 81775956 is 65957718.

It is an interprime number because it is at equal distance from previous prime (81775951) and next prime (81775961).

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81775951) 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, 3407320 + ... + 3407343.

Almost surely, 2^81775956 is an apocalyptic number.

It is an amenable number.

81775956 is an abundant number, since it is smaller than the sum of its proper divisors (109034636).

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

81775956 is a wasteful number, since it uses less digits than its factorization.

81775956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6814670 (or 6814668 counting only the distinct ones).

The product of its digits is 529200, while the sum is 48.

The square root of 81775956 is about 9043.0059161763. The cubic root of 81775956 is about 434.0521149024.

The spelling of 81775956 in words is "eighty-one million, seven hundred seventy-five thousand, nine hundred fifty-six".