20201990 has 16 divisors (see below), whose sum is σ = 36584352. Its totient is φ = 8031744.

The previous prime is 20201983. The next prime is 20202011. The reversal of 20201990 is 9910202.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4379 + ... + 7718.

It is an arithmetic number, because the mean of its divisors is an integer number (2286522).

Almost surely, 2^20201990 is an apocalyptic number.

20201990 is a deficient number, since it is larger than the sum of its proper divisors (16382362).

20201990 is a wasteful number, since it uses less digits than its factorization.

20201990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12271.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 20201990 is about 4494.6623899910. The cubic root of 20201990 is about 272.3525111586.

The spelling of 20201990 in words is "twenty million, two hundred one thousand, nine hundred ninety".