16421990 has 16 divisors (see below), whose sum is σ = 31833648. Its totient is φ = 6063456.

The previous prime is 16421963. The next prime is 16422019. The reversal of 16421990 is 9912461.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 63032 + ... + 63291.

It is an arithmetic number, because the mean of its divisors is an integer number (1989603).

Almost surely, 2^16421990 is an apocalyptic number.

16421990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16421990 is a deficient number, since it is larger than the sum of its proper divisors (15411658).

16421990 is a wasteful number, since it uses less digits than its factorization.

16421990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126343.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 16421990 is about 4052.4054584901. The cubic root of 16421990 is about 254.1803233129.

The spelling of 16421990 in words is "sixteen million, four hundred twenty-one thousand, nine hundred ninety".