20402311 has 4 divisors (see below), whose sum is σ = 21289392. Its totient is φ = 19515232.

The previous prime is 20402287. The next prime is 20402321. The reversal of 20402311 is 11320402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20402311 - 2¹³ = 20394119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20402291 and 20402300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 443506 + ... + 443551.

It is an arithmetic number, because the mean of its divisors is an integer number (5322348).

Almost surely, 2^20402311 is an apocalyptic number.

20402311 is a deficient number, since it is larger than the sum of its proper divisors (887081).

20402311 is an equidigital number, since it uses as much as digits as its factorization.

20402311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887080.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20402311 is about 4516.8917410095. The cubic root of 20402311 is about 273.2497591341.

Adding to 20402311 its reverse (11320402), we get a palindrome (31722713).

The spelling of 20402311 in words is "twenty million, four hundred two thousand, three hundred eleven".