20645955 has 32 divisors (see below), whose sum is σ = 40043520. Its totient is φ = 10009440.

The previous prime is 20645921. The next prime is 20645957. The reversal of 20645955 is 55954602.

20645955 is a `hidden beast` number, since 2 + 0 + 64 + 595 + 5 = 666.

It is not a de Polignac number, because 20645955 - 2⁷ = 20645827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20645957) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5467 + ... + 8436.

It is an arithmetic number, because the mean of its divisors is an integer number (1251360).

Almost surely, 2^20645955 is an apocalyptic number.

20645955 is a deficient number, since it is larger than the sum of its proper divisors (19397565).

20645955 is a wasteful number, since it uses less digits than its factorization.

20645955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13928 (or 13922 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 20645955 is about 4543.7820150179. The cubic root of 20645955 is about 274.3331722430. Note that the first 3 decimals are identical.

The spelling of 20645955 in words is "twenty million, six hundred forty-five thousand, nine hundred fifty-five".