81451685952 has 168 divisors, whose sum is σ = 287343632576. Its totient is φ = 21481749504.

The previous prime is 81451685951. The next prime is 81451685957. The reversal of 81451685952 is 25958615418.

81451685952 is a `hidden beast` number, since 8 + 1 + 45 + 1 + 6 + 8 + 595 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

It is not an unprimeable number, because it can be changed into a prime (81451685951) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 724558 + ... + 829389.

Almost surely, 2^81451685952 is an apocalyptic number.

It is an amenable number.

81451685952 is an abundant number, since it is smaller than the sum of its proper divisors (205891946624).

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

81451685952 is a wasteful number, since it uses less digits than its factorization.

81451685952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1553985 (or 1553972 counting only the distinct ones).

The product of its digits is 3456000, while the sum is 54.

The spelling of 81451685952 in words is "eighty-one billion, four hundred fifty-one million, six hundred eighty-five thousand, nine hundred fifty-two".