20966990 has 32 divisors (see below), whose sum is σ = 42184800. Its totient is φ = 7436800.

The previous prime is 20966983. The next prime is 20966993. The reversal of 20966990 is 9966902.

It is a happy number.

It is a super-2 number, since 2×20966990² = 879229339320200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20966993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2186 + ... + 6834.

It is an arithmetic number, because the mean of its divisors is an integer number (1318275).

Almost surely, 2^20966990 is an apocalyptic number.

20966990 is an abundant number, since it is smaller than the sum of its proper divisors (21217810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20966990 is a wasteful number, since it uses less digits than its factorization.

20966990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4708.

The product of its (nonzero) digits is 52488, while the sum is 41.

The square root of 20966990 is about 4578.9725921870. The cubic root of 20966990 is about 275.7477829593.

The spelling of 20966990 in words is "twenty million, nine hundred sixty-six thousand, nine hundred ninety".