81677900 has 18 divisors (see below), whose sum is σ = 177241260. Its totient is φ = 32671120.

The previous prime is 81677887. The next prime is 81677909. The reversal of 81677900 is 977618.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81677909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 408290 + ... + 408489.

Almost surely, 2^81677900 is an apocalyptic number.

It is an amenable number.

81677900 is an abundant number, since it is smaller than the sum of its proper divisors (95563360).

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

81677900 is a wasteful number, since it uses less digits than its factorization.

81677900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816793 (or 816786 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 38.

The square root of 81677900 is about 9037.5826413926. The cubic root of 81677900 is about 433.8785576242.

The spelling of 81677900 in words is "eighty-one million, six hundred seventy-seven thousand, nine hundred".