20315749 has 2 divisors, whose sum is σ = 20315750. Its totient is φ = 20315748.

The previous prime is 20315723. The next prime is 20315761. The reversal of 20315749 is 94751302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15444900 + 4870849 = 3930^2 + 2207^2 .

It is a cyclic number.

It is not a de Polignac number, because 20315749 - 2¹¹ = 20313701 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20315749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20315549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10157874 + 10157875.

It is an arithmetic number, because the mean of its divisors is an integer number (10157875).

Almost surely, 2^20315749 is an apocalyptic number.

It is an amenable number.

20315749 is a deficient number, since it is larger than the sum of its proper divisors (1).

20315749 is an equidigital number, since it uses as much as digits as its factorization.

20315749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 20315749 is about 4507.2995241053. The cubic root of 20315749 is about 272.8627674173.

The spelling of 20315749 in words is "twenty million, three hundred fifteen thousand, seven hundred forty-nine".