18401971 has 16 divisors (see below), whose sum is σ = 21622464. Its totient is φ = 15335424.

The previous prime is 18401969. The next prime is 18401983. The reversal of 18401971 is 17910481.

It is a cyclic number.

It is not a de Polignac number, because 18401971 - 2¹ = 18401969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18401371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71475 + ... + 71731.

It is an arithmetic number, because the mean of its divisors is an integer number (1351404).

Almost surely, 2^18401971 is an apocalyptic number.

18401971 is a deficient number, since it is larger than the sum of its proper divisors (3220493).

18401971 is a wasteful number, since it uses less digits than its factorization.

18401971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 18401971 is about 4289.7518576253. The cubic root of 18401971 is about 264.0106505881.

The spelling of 18401971 in words is "eighteen million, four hundred one thousand, nine hundred seventy-one".