81051764 has 12 divisors (see below), whose sum is σ = 142365888. Its totient is φ = 40375800.

The previous prime is 81051743. The next prime is 81051791. The reversal of 81051764 is 46715018.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81051764.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36302 + ... + 38469.

It is an arithmetic number, because the mean of its divisors is an integer number (11863824).

Almost surely, 2^81051764 is an apocalyptic number.

It is an amenable number.

81051764 is a deficient number, since it is larger than the sum of its proper divisors (61314124).

81051764 is a wasteful number, since it uses less digits than its factorization.

81051764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75046 (or 75044 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 81051764 is about 9002.8753184746. The cubic root of 81051764 is about 432.7670201157.

The spelling of 81051764 in words is "eighty-one million, fifty-one thousand, seven hundred sixty-four".