20961790 has 16 divisors (see below), whose sum is σ = 38079360. Its totient is φ = 8307360.

The previous prime is 20961779. The next prime is 20961793. The reversal of 20961790 is 9716902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20961793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8526 + ... + 10705.

It is an arithmetic number, because the mean of its divisors is an integer number (2379960).

Almost surely, 2^20961790 is an apocalyptic number.

20961790 is a deficient number, since it is larger than the sum of its proper divisors (17117570).

20961790 is a wasteful number, since it uses less digits than its factorization.

20961790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19347.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 20961790 is about 4578.4047440129. The cubic root of 20961790 is about 275.7249851069.

The spelling of 20961790 in words is "twenty million, nine hundred sixty-one thousand, seven hundred ninety".