81461490 has 64 divisors (see below), whose sum is σ = 220188672. Its totient is φ = 19108800.

The previous prime is 81461489. The next prime is 81461507. The reversal of 81461490 is 9416418.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6249 + ... + 14211.

It is an arithmetic number, because the mean of its divisors is an integer number (3440448).

Almost surely, 2^81461490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81461490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110094336).

81461490 is an abundant number, since it is smaller than the sum of its proper divisors (138727182).

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

81461490 is a wasteful number, since it uses less digits than its factorization.

81461490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8015.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 81461490 is about 9025.6019189858. The cubic root of 81461490 is about 433.4950238158.

The spelling of 81461490 in words is "eighty-one million, four hundred sixty-one thousand, four hundred ninety".