181017972 has 72 divisors (see below), whose sum is σ = 486997056. Its totient is φ = 56496384.

The previous prime is 181017961. The next prime is 181017983. The reversal of 181017972 is 279710181.

181017972 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (181017961) and next prime (181017983).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138273 + ... + 139575.

It is an arithmetic number, because the mean of its divisors is an integer number (6763848).

Almost surely, 2^181017972 is an apocalyptic number.

181017972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181017972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243498528).

181017972 is an abundant number, since it is smaller than the sum of its proper divisors (305979084).

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

181017972 is a wasteful number, since it uses less digits than its factorization.

181017972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1557 (or 1552 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 36.

The square root of 181017972 is about 13454.2919546143. The cubic root of 181017972 is about 565.6840041293.

The spelling of 181017972 in words is "one hundred eighty-one million, seventeen thousand, nine hundred seventy-two".