20961550 has 12 divisors (see below), whose sum is σ = 38988576. Its totient is φ = 8384600.

The previous prime is 20961529. The next prime is 20961557. The reversal of 20961550 is 5516902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20961557) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 209566 + ... + 209665.

It is an arithmetic number, because the mean of its divisors is an integer number (3249048).

Almost surely, 2^20961550 is an apocalyptic number.

20961550 is a deficient number, since it is larger than the sum of its proper divisors (18027026).

20961550 is a wasteful number, since it uses less digits than its factorization.

20961550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419243 (or 419238 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 20961550 is about 4578.3785339353. The cubic root of 20961550 is about 275.7239328073.

The spelling of 20961550 in words is "twenty million, nine hundred sixty-one thousand, five hundred fifty".