20657365 has 4 divisors (see below), whose sum is σ = 24788844. Its totient is φ = 16525888.

The previous prime is 20657347. The next prime is 20657383. The reversal of 20657365 is 56375602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56375602 = 2 ⋅28187801.

It is an interprime number because it is at equal distance from previous prime (20657347) and next prime (20657383).

It can be written as a sum of positive squares in 2 ways, for example, as 4157521 + 16499844 = 2039^2 + 4062^2 .

It is a cyclic number.

It is not a de Polignac number, because 20657365 - 2¹³ = 20649173 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 20657365.

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, 2065732 + ... + 2065741.

It is an arithmetic number, because the mean of its divisors is an integer number (6197211).

Almost surely, 2^20657365 is an apocalyptic number.

It is an amenable number.

20657365 is a deficient number, since it is larger than the sum of its proper divisors (4131479).

20657365 is an equidigital number, since it uses as much as digits as its factorization.

20657365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4131478.

The product of its (nonzero) digits is 37800, while the sum is 34.

The square root of 20657365 is about 4545.0374035865. The cubic root of 20657365 is about 274.3836997361.

The spelling of 20657365 in words is "twenty million, six hundred fifty-seven thousand, three hundred sixty-five".