20849555 has 12 divisors (see below), whose sum is σ = 26407872. Its totient is φ = 15800400.

The previous prime is 20849551. The next prime is 20849561. The reversal of 20849555 is 55594802.

It is not a de Polignac number, because 20849555 - 2² = 20849551 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (20849551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3971 + ... + 7580.

It is an arithmetic number, because the mean of its divisors is an integer number (2200656).

Almost surely, 2^20849555 is an apocalyptic number.

20849555 is a deficient number, since it is larger than the sum of its proper divisors (5558317).

20849555 is a wasteful number, since it uses less digits than its factorization.

20849555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11594 (or 11575 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 38.

The square root of 20849555 is about 4566.1312946520. The cubic root of 20849555 is about 275.2320025641.

The spelling of 20849555 in words is "twenty million, eight hundred forty-nine thousand, five hundred fifty-five".