20965890 has 32 divisors (see below), whose sum is σ = 54893376. Its totient is φ = 5082560.

The previous prime is 20965849. The next prime is 20965891. The reversal of 20965890 is 9856902.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20965891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31437 + ... + 32096.

It is an arithmetic number, because the mean of its divisors is an integer number (1715418).

Almost surely, 2^20965890 is an apocalyptic number.

20965890 is an abundant number, since it is smaller than the sum of its proper divisors (33927486).

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

20965890 is a wasteful number, since it uses less digits than its factorization.

20965890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63554.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 20965890 is about 4578.8524763307. The cubic root of 20965890 is about 275.7429606510.

The spelling of 20965890 in words is "twenty million, nine hundred sixty-five thousand, eight hundred ninety".