20645756 has 6 divisors (see below), whose sum is σ = 36130080. Its totient is φ = 10322876.

The previous prime is 20645753. The next prime is 20645791. The reversal of 20645756 is 65754602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2580716 + ... + 2580723.

It is an arithmetic number, because the mean of its divisors is an integer number (6021680).

Almost surely, 2^20645756 is an apocalyptic number.

It is an amenable number.

20645756 is a deficient number, since it is larger than the sum of its proper divisors (15484324).

20645756 is a wasteful number, since it uses less digits than its factorization.

20645756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5161443 (or 5161441 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 35.

The square root of 20645756 is about 4543.7601169076. The cubic root of 20645756 is about 274.3322908358.

The spelling of 20645756 in words is "twenty million, six hundred forty-five thousand, seven hundred fifty-six".