81451700 has 36 divisors (see below), whose sum is σ = 192820992. Its totient is φ = 29618400.

The previous prime is 81451681. The next prime is 81451723. The reversal of 81451700 is 715418.

It is a self number, because there is not a number n which added to its sum of digits gives 81451700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35924 + ... + 38123.

Almost surely, 2^81451700 is an apocalyptic number.

It is an amenable number.

81451700 is an abundant number, since it is smaller than the sum of its proper divisors (111369292).

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

81451700 is a wasteful number, since it uses less digits than its factorization.

81451700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74072 (or 74065 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 81451700 is about 9025.0595565902. The cubic root of 81451700 is about 433.4776573837.

The spelling of 81451700 in words is "eighty-one million, four hundred fifty-one thousand, seven hundred".