20840550 has 24 divisors (see below), whose sum is σ = 51684936. Its totient is φ = 5557440.

The previous prime is 20840543. The next prime is 20840557. The reversal of 20840550 is 5504802.

It is an interprime number because it is at equal distance from previous prime (20840543) and next prime (20840557).

It is a self number, because there is not a number n which added to its sum of digits gives 20840550.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20840557) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69319 + ... + 69618.

It is an arithmetic number, because the mean of its divisors is an integer number (2153539).

Almost surely, 2^20840550 is an apocalyptic number.

20840550 is an abundant number, since it is smaller than the sum of its proper divisors (30844386).

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

20840550 is a wasteful number, since it uses less digits than its factorization.

20840550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138952 (or 138947 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 20840550 is about 4565.1451236516. The cubic root of 20840550 is about 275.1923722844.

The spelling of 20840550 in words is "twenty million, eight hundred forty thousand, five hundred fifty".