81900088 has 8 divisors (see below), whose sum is σ = 153562680. Its totient is φ = 40950040.

The previous prime is 81900061. The next prime is 81900097. The reversal of 81900088 is 88000918.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5118748 + ... + 5118763.

It is an arithmetic number, because the mean of its divisors is an integer number (19195335).

Almost surely, 2^81900088 is an apocalyptic number.

It is an amenable number.

81900088 is a deficient number, since it is larger than the sum of its proper divisors (71662592).

81900088 is a wasteful number, since it uses less digits than its factorization.

81900088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10237517 (or 10237513 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 34.

The square root of 81900088 is about 9049.8667393504. The cubic root of 81900088 is about 434.2716273379.

The spelling of 81900088 in words is "eighty-one million, nine hundred thousand, eighty-eight".