81319470 has 16 divisors (see below), whose sum is σ = 195166800. Its totient is φ = 21685184.

The previous prime is 81319457. The next prime is 81319531. The reversal of 81319470 is 7491318.

It is a super-2 number, since 2×81319470² = 13225712402161800, 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 7 ways as a sum of consecutive naturals, for example, 1355295 + ... + 1355354.

It is an arithmetic number, because the mean of its divisors is an integer number (12197925).

Almost surely, 2^81319470 is an apocalyptic number.

81319470 is an abundant number, since it is smaller than the sum of its proper divisors (113847330).

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

81319470 is a wasteful number, since it uses less digits than its factorization.

81319470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2710659.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 81319470 is about 9017.7308675742. The cubic root of 81319470 is about 433.2429587994.

The spelling of 81319470 in words is "eighty-one million, three hundred nineteen thousand, four hundred seventy".