20311213 has 8 divisors (see below), whose sum is σ = 21929600. Its totient is φ = 18700848.

The previous prime is 20311211. The next prime is 20311273. The reversal of 20311213 is 31211302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20311213 - 2¹ = 20311211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20311193 and 20311202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20311211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3928 + ... + 7486.

It is an arithmetic number, because the mean of its divisors is an integer number (2741200).

Almost surely, 2^20311213 is an apocalyptic number.

It is an amenable number.

20311213 is a deficient number, since it is larger than the sum of its proper divisors (1618387).

20311213 is a wasteful number, since it uses less digits than its factorization.

20311213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4011.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 20311213 is about 4506.7963122378. The cubic root of 20311213 is about 272.8424580891.

Adding to 20311213 its reverse (31211302), we get a palindrome (51522515).

The spelling of 20311213 in words is "twenty million, three hundred eleven thousand, two hundred thirteen".