81451512 has 24 divisors (see below), whose sum is σ = 220598040. Its totient is φ = 27150480.

The previous prime is 81451507. The next prime is 81451523. The reversal of 81451512 is 21515418.

81451512 is a `hidden beast` number, since 8 + 145 + 1 + 512 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×81451512² = 13268697614172288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 565564 + ... + 565707.

It is an arithmetic number, because the mean of its divisors is an integer number (9191585).

Almost surely, 2^81451512 is an apocalyptic number.

It is an amenable number.

81451512 is an abundant number, since it is smaller than the sum of its proper divisors (139146528).

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

81451512 is a wasteful number, since it uses less digits than its factorization.

81451512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131283 (or 1131276 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The square root of 81451512 is about 9025.0491411405. The cubic root of 81451512 is about 433.4773238778.

It can be divided in two parts, 814 and 51512, that added together give a triangular number (52326 = T₃₂₃).

The spelling of 81451512 in words is "eighty-one million, four hundred fifty-one thousand, five hundred twelve".