18890531 has 4 divisors (see below), whose sum is σ = 20607864. Its totient is φ = 17173200.

The previous prime is 18890507. The next prime is 18890537. The reversal of 18890531 is 13509881.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 18890531 - 2⁶ = 18890467 is a prime.

It is a super-2 number, since 2×18890531² = 713704322923922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18890491 and 18890500.

It is not an unprimeable number, because it can be changed into a prime (18890537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 858650 + ... + 858671.

It is an arithmetic number, because the mean of its divisors is an integer number (5151966).

Almost surely, 2^18890531 is an apocalyptic number.

18890531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18890531 is a deficient number, since it is larger than the sum of its proper divisors (1717333).

18890531 is a wasteful number, since it uses less digits than its factorization.

18890531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1717332.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 18890531 is about 4346.3238489556. The cubic root of 18890531 is about 266.3267086315.

The spelling of 18890531 in words is "eighteen million, eight hundred ninety thousand, five hundred thirty-one".