81927900 has 216 divisors, whose sum is σ = 275555280. Its totient is φ = 20321280.

The previous prime is 81927887. The next prime is 81927917. The reversal of 81927900 is 972918.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1122264 + ... + 1122336.

Almost surely, 2^81927900 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81927900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137777640).

81927900 is an abundant number, since it is smaller than the sum of its proper divisors (193627380).

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

81927900 is a wasteful number, since it uses less digits than its factorization.

81927900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 81927900 is about 9051.4032061333. The cubic root of 81927900 is about 434.3207790783.

The spelling of 81927900 in words is "eighty-one million, nine hundred twenty-seven thousand, nine hundred".