131221145 has 16 divisors (see below), whose sum is σ = 172184832. Its totient is φ = 95208960.

The previous prime is 131221121. The next prime is 131221151. The reversal of 131221145 is 541122131.

It is not a de Polignac number, because 131221145 - 2¹² = 131217049 is a prime.

It is a super-2 number, since 2×131221145² = 34437977790222050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

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, 22889 + ... + 28041.

It is an arithmetic number, because the mean of its divisors is an integer number (10761552).

Almost surely, 2^131221145 is an apocalyptic number.

It is an amenable number.

131221145 is a deficient number, since it is larger than the sum of its proper divisors (40963687).

131221145 is a wasteful number, since it uses less digits than its factorization.

131221145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5632.

The product of its digits is 240, while the sum is 20.

The square root of 131221145 is about 11455.1798327220. The cubic root of 131221145 is about 508.1609336247.

Adding to 131221145 its reverse (541122131), we get a palindrome (672343276).

The spelling of 131221145 in words is "one hundred thirty-one million, two hundred twenty-one thousand, one hundred forty-five".