1221020131 has 8 divisors (see below), whose sum is σ = 1252729280. Its totient is φ = 1189461672.

The previous prime is 1221020117. The next prime is 1221020137. The reversal of 1221020131 is 1310201221.

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 1221020131 - 2⁹ = 1221019619 is a prime.

It is a super-2 number, since 2×1221020131² = 2981780320614514322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221020137) 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, 21165 + ... + 53758.

It is an arithmetic number, because the mean of its divisors is an integer number (156591160).

Almost surely, 2^1221020131 is an apocalyptic number.

1221020131 is a deficient number, since it is larger than the sum of its proper divisors (31709149).

1221020131 is an equidigital number, since it uses as much as digits as its factorization.

1221020131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75345.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1221020131 is about 34943.0984745200. The cubic root of 1221020131 is about 1068.8274723955.

Adding to 1221020131 its reverse (1310201221), we get a palindrome (2531221352).

The spelling of 1221020131 in words is "one billion, two hundred twenty-one million, twenty thousand, one hundred thirty-one".