81435900 has 288 divisors, whose sum is σ = 307202560. Its totient is φ = 16174080.

The previous prime is 81435889. The next prime is 81435911. The reversal of 81435900 is 953418.

It is an interprime number because it is at equal distance from previous prime (81435889) and next prime (81435911).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 518622 + ... + 518778.

Almost surely, 2^81435900 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 81435900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153601280).

81435900 is an abundant number, since it is smaller than the sum of its proper divisors (225766660).

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

81435900 is a wasteful number, since it uses less digits than its factorization.

81435900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 81435900 is about 9024.1841736525. The cubic root of 81435900 is about 433.4496269072.

The spelling of 81435900 in words is "eighty-one million, four hundred thirty-five thousand, nine hundred".