20393990 has 16 divisors (see below), whose sum is σ = 36812880. Its totient is φ = 8134560.

The previous prime is 20393983. The next prime is 20394037. The reversal of 20393990 is 9939302.

It is a self number, because there is not a number n which added to its sum of digits gives 20393990.

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, 1100 + ... + 6480.

It is an arithmetic number, because the mean of its divisors is an integer number (2300805).

Almost surely, 2^20393990 is an apocalyptic number.

20393990 is a deficient number, since it is larger than the sum of its proper divisors (16418890).

20393990 is a wasteful number, since it uses less digits than its factorization.

20393990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5767.

The product of its (nonzero) digits is 13122, while the sum is 35.

The square root of 20393990 is about 4515.9705490625. The cubic root of 20393990 is about 273.2126061464.

The spelling of 20393990 in words is "twenty million, three hundred ninety-three thousand, nine hundred ninety".