20645149 has 16 divisors (see below), whose sum is σ = 24563200. Its totient is φ = 16982784.

The previous prime is 20645147. The next prime is 20645161. The reversal of 20645149 is 94154602.

It is not a de Polignac number, because 20645149 - 2¹ = 20645147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20645149.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645147) 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, 19957 + ... + 20965.

It is an arithmetic number, because the mean of its divisors is an integer number (1535200).

Almost surely, 2^20645149 is an apocalyptic number.

It is an amenable number.

20645149 is a deficient number, since it is larger than the sum of its proper divisors (3918051).

20645149 is a wasteful number, since it uses less digits than its factorization.

20645149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 20645149 is about 4543.6933215172. The cubic root of 20645149 is about 274.3296022876.

The spelling of 20645149 in words is "twenty million, six hundred forty-five thousand, one hundred forty-nine".