20756645 has 48 divisors (see below), whose sum is σ = 32941440. Its totient is φ = 12446784.

The previous prime is 20756633. The next prime is 20756699. The reversal of 20756645 is 54665702.

It is not a de Polignac number, because 20756645 - 2⁴ = 20756629 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1092446 + ... + 1092464.

It is an arithmetic number, because the mean of its divisors is an integer number (686280).

Almost surely, 2^20756645 is an apocalyptic number.

It is an amenable number.

20756645 is a deficient number, since it is larger than the sum of its proper divisors (12184795).

20756645 is an frugal number, since it uses more digits than its factorization.

20756645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 44 counting only the distinct ones).

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

The square root of 20756645 is about 4555.9461146945. The cubic root of 20756645 is about 274.8225632240.

The spelling of 20756645 in words is "twenty million, seven hundred fifty-six thousand, six hundred forty-five".