81451602 has 32 divisors (see below), whose sum is σ = 188876160. Its totient is φ = 25969680.

The previous prime is 81451547. The next prime is 81451603. The reversal of 81451602 is 20615418.

81451602 is a `hidden beast` number, since 8 + 1 + 4 + 51 + 602 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81451603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31549 + ... + 34032.

It is an arithmetic number, because the mean of its divisors is an integer number (5902380).

Almost surely, 2^81451602 is an apocalyptic number.

81451602 is an abundant number, since it is smaller than the sum of its proper divisors (107424558).

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

81451602 is a wasteful number, since it uses less digits than its factorization.

81451602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65615 (or 65609 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 81451602 is about 9025.0541272615. The cubic root of 81451602 is about 433.4774835349.

The spelling of 81451602 in words is "eighty-one million, four hundred fifty-one thousand, six hundred two".