81319460 has 12 divisors (see below), whose sum is σ = 170770908. Its totient is φ = 32527776.

The previous prime is 81319457. The next prime is 81319531. The reversal of 81319460 is 6491318.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15936064 + 65383396 = 3992^2 + 8086^2 .

It is a super-2 number, since 2×81319460² = 13225709149383200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2032967 + ... + 2033006.

It is an arithmetic number, because the mean of its divisors is an integer number (14230909).

Almost surely, 2^81319460 is an apocalyptic number.

It is an amenable number.

81319460 is an abundant number, since it is smaller than the sum of its proper divisors (89451448).

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

81319460 is a wasteful number, since it uses less digits than its factorization.

81319460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4065982 (or 4065980 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 81319460 is about 9017.7303131109. The cubic root of 81319460 is about 433.2429410405.

The spelling of 81319460 in words is "eighty-one million, three hundred nineteen thousand, four hundred sixty".