20311745 has 16 divisors (see below), whose sum is σ = 25436160. Its totient is φ = 15551424.

The previous prime is 20311723. The next prime is 20311763. The reversal of 20311745 is 54711302.

It is not a de Polignac number, because 20311745 - 2¹² = 20307649 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20311745.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17864 + ... + 18966.

It is an arithmetic number, because the mean of its divisors is an integer number (1589760).

Almost surely, 2^20311745 is an apocalyptic number.

It is an amenable number.

20311745 is a deficient number, since it is larger than the sum of its proper divisors (5124415).

20311745 is a wasteful number, since it uses less digits than its factorization.

20311745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1264.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 20311745 is about 4506.8553338220. The cubic root of 20311745 is about 272.8448402039.

The spelling of 20311745 in words is "twenty million, three hundred eleven thousand, seven hundred forty-five".