81992469240 has 256 divisors, whose sum is σ = 303044889600. Its totient is φ = 19550937600.

The previous prime is 81992469233. The next prime is 81992469269. The reversal of 81992469240 is 4296429918.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 668109 + ... + 781251.

It is an arithmetic number, because the mean of its divisors is an integer number (1183769100).

Almost surely, 2^81992469240 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 81992469240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151522444800).

81992469240 is an abundant number, since it is smaller than the sum of its proper divisors (221052420360).

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

81992469240 is a wasteful number, since it uses less digits than its factorization.

81992469240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113235 (or 113225 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The spelling of 81992469240 in words is "eighty-one billion, nine hundred ninety-two million, four hundred sixty-nine thousand, two hundred forty".