131220001 has 4 divisors (see below), whose sum is σ = 143149104. Its totient is φ = 119290900.

The previous prime is 131219989. The next prime is 131220017. The reversal of 131220001 is 100022131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 131220001 - 2⁷ = 131219873 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 131220001.

It is not an unprimeable number, because it can be changed into a prime (131220101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5964535 + ... + 5964556.

It is an arithmetic number, because the mean of its divisors is an integer number (35787276).

Almost surely, 2^131220001 is an apocalyptic number.

131220001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

131220001 is a deficient number, since it is larger than the sum of its proper divisors (11929103).

131220001 is a wasteful number, since it uses less digits than its factorization.

131220001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11929102.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 131220001 is about 11455.1298988706. The cubic root of 131220001 is about 508.1594568866.

Adding to 131220001 its reverse (100022131), we get a palindrome (231242132).

The spelling of 131220001 in words is "one hundred thirty-one million, two hundred twenty thousand, one".