18491472 has 30 divisors (see below), whose sum is σ = 51750842. Its totient is φ = 6163776.

The previous prime is 18491467. The next prime is 18491477. The reversal of 18491472 is 27419481.

18491472 is a `hidden beast` number, since 184 + 9 + 1 + 472 = 666.

It is an interprime number because it is at equal distance from previous prime (18491467) and next prime (18491477).

It can be written as a sum of positive squares in only one way, i.e., 16842816 + 1648656 = 4104^2 + 1284^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18491477) 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, 64063 + ... + 64350.

Almost surely, 2^18491472 is an apocalyptic number.

18491472 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18491472 is an abundant number, since it is smaller than the sum of its proper divisors (33259370).

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

18491472 is a wasteful number, since it uses less digits than its factorization.

18491472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128427 (or 128418 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 18491472 is about 4300.1711593842. The cubic root of 18491472 is about 264.4379782228.

It can be divided in two parts, 1849 and 1472, that added together give a triangular number (3321 = T₈₁).

The spelling of 18491472 in words is "eighteen million, four hundred ninety-one thousand, four hundred seventy-two".