16890621 has 16 divisors (see below), whose sum is σ = 24642048. Its totient is φ = 10206000.

The previous prime is 16890607. The next prime is 16890631. The reversal of 16890621 is 12609861.

It is not a de Polignac number, because 16890621 - 2⁷ = 16890493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16890631) 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, 15546 + ... + 16596.

It is an arithmetic number, because the mean of its divisors is an integer number (1540128).

Almost surely, 2^16890621 is an apocalyptic number.

16890621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16890621 is a deficient number, since it is larger than the sum of its proper divisors (7751427).

16890621 is a wasteful number, since it uses less digits than its factorization.

16890621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1552.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 16890621 is about 4109.8200690541. The cubic root of 16890621 is about 256.5755128795.

The spelling of 16890621 in words is "sixteen million, eight hundred ninety thousand, six hundred twenty-one".