81436740 has 96 divisors (see below), whose sum is σ = 284304384. Its totient is φ = 16920960.

The previous prime is 81436723. The next prime is 81436753. The reversal of 81436740 is 4763418.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4194 + ... + 13433.

It is an arithmetic number, because the mean of its divisors is an integer number (2961504).

Almost surely, 2^81436740 is an apocalyptic number.

It is an amenable number.

81436740 is an abundant number, since it is smaller than the sum of its proper divisors (202867644).

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

81436740 is a wasteful number, since it uses less digits than its factorization.

81436740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17657 (or 17655 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 81436740 is about 9024.2307151358. The cubic root of 81436740 is about 433.4511172263.

The spelling of 81436740 in words is "eighty-one million, four hundred thirty-six thousand, seven hundred forty".