20695645 has 4 divisors (see below), whose sum is σ = 24834780. Its totient is φ = 16556512.

The previous prime is 20695643. The next prime is 20695657. The reversal of 20695645 is 54659602.

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 13155129 + 7540516 = 3627^2 + 2746^2 .

It is a cyclic number.

It is not a de Polignac number, because 20695645 - 2¹ = 20695643 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20695643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2069560 + ... + 2069569.

It is an arithmetic number, because the mean of its divisors is an integer number (6208695).

Almost surely, 2^20695645 is an apocalyptic number.

It is an amenable number.

20695645 is a deficient number, since it is larger than the sum of its proper divisors (4139135).

20695645 is an equidigital number, since it uses as much as digits as its factorization.

20695645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4139134.

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 20695645 is about 4549.2466409286. The cubic root of 20695645 is about 274.5530812419.

It can be divided in two parts, 20 and 695645, that multiplied together give a square (13912900 = 3730²).

The spelling of 20695645 in words is "twenty million, six hundred ninety-five thousand, six hundred forty-five".