18631172 has 36 divisors (see below), whose sum is σ = 39931920. Its totient is φ = 7563024.

The previous prime is 18631157. The next prime is 18631187. The reversal of 18631172 is 27113681.

It is an interprime number because it is at equal distance from previous prime (18631157) and next prime (18631187).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1223 + ... + 6225.

It is an arithmetic number, because the mean of its divisors is an integer number (1109220).

Almost surely, 2^18631172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18631172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19965960).

18631172 is an abundant number, since it is smaller than the sum of its proper divisors (21300748).

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

18631172 is a wasteful number, since it uses less digits than its factorization.

18631172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5040 (or 5031 counting only the distinct ones).

The product of its digits is 2016, while the sum is 29.

The square root of 18631172 is about 4316.3841348981. The cubic root of 18631172 is about 265.1022365698.

The spelling of 18631172 in words is "eighteen million, six hundred thirty-one thousand, one hundred seventy-two".