18071972 has 6 divisors (see below), whose sum is σ = 31625958. Its totient is φ = 9035984.

The previous prime is 18071971. The next prime is 18071981. The reversal of 18071972 is 27917081.

It can be written as a sum of positive squares in only one way, i.e., 15952036 + 2119936 = 3994^2 + 1456^2 .

It is not an unprimeable number, because it can be changed into a prime (18071971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2258993 + ... + 2259000.

It is an arithmetic number, because the mean of its divisors is an integer number (5270993).

Almost surely, 2^18071972 is an apocalyptic number.

It is an amenable number.

18071972 is a deficient number, since it is larger than the sum of its proper divisors (13553986).

18071972 is a wasteful number, since it uses less digits than its factorization.

18071972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4517997 (or 4517995 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 18071972 is about 4251.1142068874. The cubic root of 18071972 is about 262.4229712006.

The spelling of 18071972 in words is "eighteen million, seventy-one thousand, nine hundred seventy-two".