81461376 has 144 divisors (see below), whose sum is σ = 245926590. Its totient is φ = 26873856.

The previous prime is 81461333. The next prime is 81461381. The reversal of 81461376 is 67316418.

It can be written as a sum of positive squares in only one way, i.e., 70963776 + 10497600 = 8424^2 + 3240^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81461376.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 839760 + ... + 839856.

Almost surely, 2^81461376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81461376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122963295).

81461376 is an abundant number, since it is smaller than the sum of its proper divisors (164465214).

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

81461376 is an frugal number, since it uses more digits than its factorization.

81461376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 102 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 81461376 is about 9025.5956036153. The cubic root of 81461376 is about 433.4948215998.

The spelling of 81461376 in words is "eighty-one million, four hundred sixty-one thousand, three hundred seventy-six".