81144792 has 24 divisors (see below), whose sum is σ = 219767340. Its totient is φ = 27048240.

The previous prime is 81144787. The next prime is 81144793. The reversal of 81144792 is 29744118.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81144793) 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, 563434 + ... + 563577.

Almost surely, 2^81144792 is an apocalyptic number.

It is an amenable number.

81144792 is an abundant number, since it is smaller than the sum of its proper divisors (138622548).

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

81144792 is a wasteful number, since it uses less digits than its factorization.

81144792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1127023 (or 1127016 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 81144792 is about 9008.0404084351. The cubic root of 81144792 is about 432.9325277511.

The spelling of 81144792 in words is "eighty-one million, one hundred forty-four thousand, seven hundred ninety-two".