20501990 has 32 divisors (see below), whose sum is σ = 38071296. Its totient is φ = 7945600.

The previous prime is 20501989. The next prime is 20502019. The reversal of 20501990 is 9910502.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53339 + ... + 53721.

It is an arithmetic number, because the mean of its divisors is an integer number (1189728).

Almost surely, 2^20501990 is an apocalyptic number.

20501990 is a deficient number, since it is larger than the sum of its proper divisors (17569306).

20501990 is a wasteful number, since it uses less digits than its factorization.

20501990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544.

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 20501990 is about 4527.9123224727. The cubic root of 20501990 is about 273.6940392829.

The spelling of 20501990 in words is "twenty million, five hundred one thousand, nine hundred ninety".