131220311 has 4 divisors (see below), whose sum is σ = 132519624. Its totient is φ = 129921000.

The previous prime is 131220293. The next prime is 131220329. The reversal of 131220311 is 113022131.

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

It is an interprime number because it is at equal distance from previous prime (131220293) and next prime (131220329).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131220311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131220361) 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, 649505 + ... + 649706.

It is an arithmetic number, because the mean of its divisors is an integer number (33129906).

Almost surely, 2^131220311 is an apocalyptic number.

131220311 is a deficient number, since it is larger than the sum of its proper divisors (1299313).

131220311 is a wasteful number, since it uses less digits than its factorization.

131220311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1299312.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 131220311 is about 11455.1434299183. The cubic root of 131220311 is about 508.1598570525.

Adding to 131220311 its reverse (113022131), we get a palindrome (244242442).

The spelling of 131220311 in words is "one hundred thirty-one million, two hundred twenty thousand, three hundred eleven".