81099802 has 12 divisors (see below), whose sum is σ = 141511050. Its totient is φ = 34757016.

The previous prime is 81099791. The next prime is 81099803. The reversal of 81099802 is 20899018.

It can be written as a sum of positive squares in only one way, i.e., 46771921 + 34327881 = 6839^2 + 5859^2 .

It is not an unprimeable number, because it can be changed into a prime (81099803) 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, 413677 + ... + 413872.

Almost surely, 2^81099802 is an apocalyptic number.

81099802 is a deficient number, since it is larger than the sum of its proper divisors (60411248).

81099802 is a wasteful number, since it uses less digits than its factorization.

81099802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827565 (or 827558 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 81099802 is about 9005.5428487127. The cubic root of 81099802 is about 432.8525011108.

The spelling of 81099802 in words is "eighty-one million, ninety-nine thousand, eight hundred two".