81390048 has 24 divisors (see below), whose sum is σ = 213649128. Its totient is φ = 27129984.

The previous prime is 81390019. The next prime is 81390061. The reversal of 81390048 is 84009318.

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

It is a congruent number.

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, 423811 + ... + 424002.

It is an arithmetic number, because the mean of its divisors is an integer number (8902047).

Almost surely, 2^81390048 is an apocalyptic number.

It is an amenable number.

81390048 is an abundant number, since it is smaller than the sum of its proper divisors (132259080).

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

81390048 is a wasteful number, since it uses less digits than its factorization.

81390048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847826 (or 847818 counting only the distinct ones).

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

The square root of 81390048 is about 9021.6433092868. The cubic root of 81390048 is about 433.3682612215.

The spelling of 81390048 in words is "eighty-one million, three hundred ninety thousand, forty-eight".