81651296740 has 48 divisors (see below), whose sum is σ = 192686151168. Its totient is φ = 28837378944.

The previous prime is 81651296719. The next prime is 81651296743. The reversal of 81651296740 is 4769215618.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81651296743) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6821052 + ... + 6833011.

It is an arithmetic number, because the mean of its divisors is an integer number (4014294816).

Almost surely, 2^81651296740 is an apocalyptic number.

It is an amenable number.

81651296740 is an abundant number, since it is smaller than the sum of its proper divisors (111034854428).

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

81651296740 is a wasteful number, since it uses less digits than its factorization.

81651296740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13654108 (or 13654106 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 49.

The spelling of 81651296740 in words is "eighty-one billion, six hundred fifty-one million, two hundred ninety-six thousand, seven hundred forty".