81698760 has 384 divisors, whose sum is σ = 334454400. Its totient is φ = 17487360.

The previous prime is 81698741. The next prime is 81698761. The reversal of 81698760 is 6789618.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81698761) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3552109 + ... + 3552131.

It is an arithmetic number, because the mean of its divisors is an integer number (870975).

Almost surely, 2^81698760 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 81698760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167227200).

81698760 is an abundant number, since it is smaller than the sum of its proper divisors (252755640).

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

81698760 is a wasteful number, since it uses less digits than its factorization.

81698760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 81698760 is about 9038.7366373847. The cubic root of 81698760 is about 433.9154910595.

The spelling of 81698760 in words is "eighty-one million, six hundred ninety-eight thousand, seven hundred sixty".