81490300 has 18 divisors (see below), whose sum is σ = 176834168. Its totient is φ = 32596080.

The previous prime is 81490249. The next prime is 81490303. The reversal of 81490300 is 309418.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81490303) 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, 407352 + ... + 407551.

Almost surely, 2^81490300 is an apocalyptic number.

It is an amenable number.

81490300 is an abundant number, since it is smaller than the sum of its proper divisors (95343868).

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

81490300 is a wasteful number, since it uses less digits than its factorization.

81490300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 814917 (or 814910 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 81490300 is about 9027.1977933354. The cubic root of 81490300 is about 433.5461216602.

Adding to 81490300 its reverse (309418), we get a palindrome (81799718).

The spelling of 81490300 in words is "eighty-one million, four hundred ninety thousand, three hundred".