1221347631 has 8 divisors (see below), whose sum is σ = 1861101184. Its totient is φ = 697912920.

The previous prime is 1221347591. The next prime is 1221347639. The reversal of 1221347631 is 1367431221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221347631 - 2⁹ = 1221347119 is a prime.

It is a super-2 number, since 2×1221347631² = 2983380071498624322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221347639) 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, 29079685 + ... + 29079726.

It is an arithmetic number, because the mean of its divisors is an integer number (232637648).

Almost surely, 2^1221347631 is an apocalyptic number.

1221347631 is a deficient number, since it is larger than the sum of its proper divisors (639753553).

1221347631 is an equidigital number, since it uses as much as digits as its factorization.

1221347631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58159421.

The product of its digits is 6048, while the sum is 30.

The square root of 1221347631 is about 34947.7843503705. The cubic root of 1221347631 is about 1068.9230235654.

Adding to 1221347631 its reverse (1367431221), we get a palindrome (2588778852).

The spelling of 1221347631 in words is "one billion, two hundred twenty-one million, three hundred forty-seven thousand, six hundred thirty-one".