181201631 has 6 divisors (see below), whose sum is σ = 196212600. Its totient is φ = 167262888.

The previous prime is 181201609. The next prime is 181201633. The reversal of 181201631 is 136102181.

It is not a de Polignac number, because 181201631 - 2¹⁴ = 181185247 is a prime.

It is a super-2 number, since 2×181201631² = 65668062154120322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 181201597 and 181201606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181201633) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 535931 + ... + 536268.

It is an arithmetic number, because the mean of its divisors is an integer number (32702100).

Almost surely, 2^181201631 is an apocalyptic number.

181201631 is a deficient number, since it is larger than the sum of its proper divisors (15010969).

181201631 is a wasteful number, since it uses less digits than its factorization.

181201631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072225 (or 1072212 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 181201631 is about 13461.1155184108. The cubic root of 181201631 is about 565.8752518839.

The spelling of 181201631 in words is "one hundred eighty-one million, two hundred one thousand, six hundred thirty-one".