20749837 has 2 divisors, whose sum is σ = 20749838. Its totient is φ = 20749836.

The previous prime is 20749831. The next prime is 20749879. The reversal of 20749837 is 73894702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16208676 + 4541161 = 4026^2 + 2131^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20749837 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20749837.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20749831) by changing a digit.

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 as a sum of consecutive naturals, namely, 10374918 + 10374919.

It is an arithmetic number, because the mean of its divisors is an integer number (10374919).

Almost surely, 2^20749837 is an apocalyptic number.

It is an amenable number.

20749837 is a deficient number, since it is larger than the sum of its proper divisors (1).

20749837 is an equidigital number, since it uses as much as digits as its factorization.

20749837 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 20749837 is about 4555.1988979626. The cubic root of 20749837 is about 274.7925134640.

It can be divided in two parts, 2074 and 9837, that added together give a palindrome (11911).

The spelling of 20749837 in words is "twenty million, seven hundred forty-nine thousand, eight hundred thirty-seven".