72031581769 has 27 divisors (see below), whose sum is σ = 87645937197. Its totient is φ = 59021521944.

The previous prime is 72031581767. The next prime is 72031581799. The reversal of 72031581769 is 96718513027.

It is a happy number.

The square root of 72031581769 is 268387.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 72031581769 - 2¹ = 72031581767 is a prime.

It is a super-2 number, since 2×72031581769² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (72031581761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 43209474 + ... + 43211140.

Almost surely, 2^72031581769 is an apocalyptic number.

72031581769 is the 268387-th square number.

72031581769 is the 134194-th centered octagonal number.

It is an amenable number.

72031581769 is a deficient number, since it is larger than the sum of its proper divisors (15614355428).

72031581769 is an frugal number, since it uses more digits than its factorization.

72031581769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3394 (or 1697 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 49.

Multiplying 72031581769 by its sum of digits (49), we get a square (3529547506681 = 1878709²).

72031581769 divided by its sum of digits (49) gives a square (1470032281 = 38341²).

The spelling of 72031581769 in words is "seventy-two billion, thirty-one million, five hundred eighty-one thousand, seven hundred sixty-nine".