20756345 has 4 divisors (see below), whose sum is σ = 24907620. Its totient is φ = 16605072.

The previous prime is 20756321. The next prime is 20756347. The reversal of 20756345 is 54365702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54365702 = 2 ⋅27182851.

It can be written as a sum of positive squares in 2 ways, for example, as 10445824 + 10310521 = 3232^2 + 3211^2 .

It is a cyclic number.

It is not a de Polignac number, because 20756345 - 2⁸ = 20756089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20756347) 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, 2075630 + ... + 2075639.

It is an arithmetic number, because the mean of its divisors is an integer number (6226905).

Almost surely, 2^20756345 is an apocalyptic number.

It is an amenable number.

20756345 is a deficient number, since it is larger than the sum of its proper divisors (4151275).

20756345 is an equidigital number, since it uses as much as digits as its factorization.

20756345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4151274.

The product of its (nonzero) digits is 25200, while the sum is 32.

The square root of 20756345 is about 4555.9131905689. The cubic root of 20756345 is about 274.8212391955.

The spelling of 20756345 in words is "twenty million, seven hundred fifty-six thousand, three hundred forty-five".