20823550 has 24 divisors (see below), whose sum is σ = 42253992. Its totient is φ = 7572000.

The previous prime is 20823497. The next prime is 20823553. The reversal of 20823550 is 5532802.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20823553) 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 11 ways as a sum of consecutive naturals, for example, 18381 + ... + 19480.

It is an arithmetic number, because the mean of its divisors is an integer number (1760583).

Almost surely, 2^20823550 is an apocalyptic number.

20823550 is an abundant number, since it is smaller than the sum of its proper divisors (21430442).

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

20823550 is a wasteful number, since it uses less digits than its factorization.

20823550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37884 (or 37879 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 20823550 is about 4563.2828095572. The cubic root of 20823550 is about 275.1175255241.

The spelling of 20823550 in words is "twenty million, eight hundred twenty-three thousand, five hundred fifty".