81498780 has 72 divisors (see below), whose sum is σ = 269693424. Its totient is φ = 19756800.

The previous prime is 81498763. The next prime is 81498793. The reversal of 81498780 is 8789418.

81498780 = 709² + 710² + ... + 843².

81498780 is a `hidden beast` number, since 81 + 498 + 7 + 80 = 666.

It is a super-2 number, since 2×81498780² = 13284102282976800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18601 + ... + 22560.

It is an arithmetic number, because the mean of its divisors is an integer number (3745742).

Almost surely, 2^81498780 is an apocalyptic number.

It is an amenable number.

81498780 is an abundant number, since it is smaller than the sum of its proper divisors (188194644).

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

81498780 is a wasteful number, since it uses less digits than its factorization.

81498780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41187 (or 41182 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 81498780 is about 9027.6674728304. The cubic root of 81498780 is about 433.5611596201.

The spelling of 81498780 in words is "eighty-one million, four hundred ninety-eight thousand, seven hundred eighty".