20312757 has 6 divisors (see below), whose sum is σ = 29340662. Its totient is φ = 13541832.

The previous prime is 20312713. The next prime is 20312779. The reversal of 20312757 is 75721302.

It can be written as a sum of positive squares in only one way, i.e., 18740241 + 1572516 = 4329^2 + 1254^2 .

It is not a de Polignac number, because 20312757 - 2⁶ = 20312693 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20312757.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20312057) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1128478 + ... + 1128495.

Almost surely, 2^20312757 is an apocalyptic number.

It is an amenable number.

20312757 is a deficient number, since it is larger than the sum of its proper divisors (9027905).

20312757 is a wasteful number, since it uses less digits than its factorization.

20312757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2256979 (or 2256976 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 20312757 is about 4506.9676058299. The cubic root of 20312757 is about 272.8493714803.

The spelling of 20312757 in words is "twenty million, three hundred twelve thousand, seven hundred fifty-seven".