20920990 has 8 divisors (see below), whose sum is σ = 37657800. Its totient is φ = 8368392.

The previous prime is 20920981. The next prime is 20920993. The reversal of 20920990 is 9902902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20920993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1046040 + ... + 1046059.

It is an arithmetic number, because the mean of its divisors is an integer number (4707225).

Almost surely, 2^20920990 is an apocalyptic number.

20920990 is a deficient number, since it is larger than the sum of its proper divisors (16736810).

20920990 is a wasteful number, since it uses less digits than its factorization.

20920990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2092106.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 20920990 is about 4573.9468733250. The cubic root of 20920990 is about 275.5459786700.

The spelling of 20920990 in words is "twenty million, nine hundred twenty thousand, nine hundred ninety".