20865550 has 12 divisors (see below), whose sum is σ = 38810016. Its totient is φ = 8346200.

The previous prime is 20865547. The next prime is 20865557. The reversal of 20865550 is 5556802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20865557) 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, 208606 + ... + 208705.

It is an arithmetic number, because the mean of its divisors is an integer number (3234168).

Almost surely, 2^20865550 is an apocalyptic number.

20865550 is a deficient number, since it is larger than the sum of its proper divisors (17944466).

20865550 is a wasteful number, since it uses less digits than its factorization.

20865550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417323 (or 417318 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 31.

The square root of 20865550 is about 4567.8824415696. The cubic root of 20865550 is about 275.3023671449.

The spelling of 20865550 in words is "twenty million, eight hundred sixty-five thousand, five hundred fifty".