81948870 has 48 divisors (see below), whose sum is σ = 213597072. Its totient is φ = 21798720.

The previous prime is 81948869. The next prime is 81948883. The reversal of 81948870 is 7884918.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46200 + ... + 47940.

It is an arithmetic number, because the mean of its divisors is an integer number (4449939).

Almost surely, 2^81948870 is an apocalyptic number.

81948870 is an abundant number, since it is smaller than the sum of its proper divisors (131648202).

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

81948870 is a wasteful number, since it uses less digits than its factorization.

81948870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2277 (or 2274 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 81948870 is about 9052.5615159467. The cubic root of 81948870 is about 434.3578316973.

The spelling of 81948870 in words is "eighty-one million, nine hundred forty-eight thousand, eight hundred seventy".