20649955 has 16 divisors (see below), whose sum is σ = 25331904. Its totient is φ = 16156800.

The previous prime is 20649953. The next prime is 20649973. The reversal of 20649955 is 55994602.

It is not a de Polignac number, because 20649955 - 2¹ = 20649953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20649953) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51817 + ... + 52213.

It is an arithmetic number, because the mean of its divisors is an integer number (1583244).

Almost surely, 2^20649955 is an apocalyptic number.

20649955 is a deficient number, since it is larger than the sum of its proper divisors (4681949).

20649955 is a wasteful number, since it uses less digits than its factorization.

20649955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606.

The product of its (nonzero) digits is 97200, while the sum is 40.

The square root of 20649955 is about 4544.2221556610. Note that the first 3 decimals coincide. The cubic root of 20649955 is about 274.3508877685.

The spelling of 20649955 in words is "twenty million, six hundred forty-nine thousand, nine hundred fifty-five".