1221001431 has 16 divisors (see below), whose sum is σ = 1777253856. Its totient is φ = 741090816.

The previous prime is 1221001429. The next prime is 1221001451. The reversal of 1221001431 is 1341001221.

It is not a de Polignac number, because 1221001431 - 2¹ = 1221001429 is a prime.

It is a super-2 number, since 2×1221001431² = 2981688989008095522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221001431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221001451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211590 + ... + 217283.

It is an arithmetic number, because the mean of its divisors is an integer number (111078366).

Almost surely, 2^1221001431 is an apocalyptic number.

1221001431 is a deficient number, since it is larger than the sum of its proper divisors (556252425).

1221001431 is a wasteful number, since it uses less digits than its factorization.

1221001431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428962.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1221001431 is about 34942.8308956215. The cubic root of 1221001431 is about 1068.8220159810.

Adding to 1221001431 its reverse (1341001221), we get a palindrome (2562002652).

The spelling of 1221001431 in words is "one billion, two hundred twenty-one million, one thousand, four hundred thirty-one".