18900973 has 16 divisors (see below), whose sum is σ = 23390080. Its totient is φ = 14872896.

The previous prime is 18900971. The next prime is 18900983. The reversal of 18900973 is 37900981.

It is a 3-Lehmer number, since φ(18900973) divides (18900973-1)³.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 18900973 - 2¹ = 18900971 is a prime.

It is a deceptive number, since it divides R_18900972.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18900971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20386 + ... + 21292.

It is an arithmetic number, because the mean of its divisors is an integer number (1461880).

It is a Poulet number, since it divides 2^18900972-1.

Almost surely, 2^18900973 is an apocalyptic number.

18900973 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18900973 is a deficient number, since it is larger than the sum of its proper divisors (4489107).

18900973 is a wasteful number, since it uses less digits than its factorization.

18900973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1156.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 18900973 is about 4347.5249280481. The cubic root of 18900973 is about 266.3757715057.

The spelling of 18900973 in words is "eighteen million, nine hundred thousand, nine hundred seventy-three".