20935645 has 4 divisors (see below), whose sum is σ = 25122780. Its totient is φ = 16748512.

The previous prime is 20935639. The next prime is 20935657. The reversal of 20935645 is 54653902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14243076 + 6692569 = 3774^2 + 2587^2 .

It is a cyclic number.

It is not a de Polignac number, because 20935645 - 2³ = 20935637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20935645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2093560 + ... + 2093569.

It is an arithmetic number, because the mean of its divisors is an integer number (6280695).

Almost surely, 2^20935645 is an apocalyptic number.

It is an amenable number.

20935645 is a deficient number, since it is larger than the sum of its proper divisors (4187135).

20935645 is an equidigital number, since it uses as much as digits as its factorization.

20935645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4187134.

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 20935645 is about 4575.5486009876. The cubic root of 20935645 is about 275.6103029649.

The spelling of 20935645 in words is "twenty million, nine hundred thirty-five thousand, six hundred forty-five".