81124137372 has 48 divisors (see below), whose sum is σ = 193475036160. Its totient is φ = 26444407872.

The previous prime is 81124137371. The next prime is 81124137383. The reversal of 81124137372 is 27373142118.

It is a super-2 number, since 2×81124137372² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81124137372.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81124137371) 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, 639529 + ... + 755807.

It is an arithmetic number, because the mean of its divisors is an integer number (4030729920).

Almost surely, 2^81124137372 is an apocalyptic number.

It is an amenable number.

81124137372 is an abundant number, since it is smaller than the sum of its proper divisors (112350898788).

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

81124137372 is a wasteful number, since it uses less digits than its factorization.

81124137372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117570 (or 117568 counting only the distinct ones).

The product of its digits is 56448, while the sum is 39.

The spelling of 81124137372 in words is "eighty-one billion, one hundred twenty-four million, one hundred thirty-seven thousand, three hundred seventy-two".