1221631631 has 8 divisors (see below), whose sum is σ = 1333605504. Its totient is φ = 1109810520.

The previous prime is 1221631529. The next prime is 1221631643. The reversal of 1221631631 is 1361361221.

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 1221631631 - 2¹⁰ = 1221630607 is a prime.

It is a super-2 number, since 2×1221631631² = 2984767683719440322, 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 1221631631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221631681) 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, 21131 + ... + 53756.

It is an arithmetic number, because the mean of its divisors is an integer number (166700688).

Almost surely, 2^1221631631 is an apocalyptic number.

1221631631 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221631631 is a deficient number, since it is larger than the sum of its proper divisors (111973873).

1221631631 is a wasteful number, since it uses less digits than its factorization.

1221631631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76381.

The product of its digits is 1296, while the sum is 26.

The square root of 1221631631 is about 34951.8473188471. The cubic root of 1221631631 is about 1069.0058693782.

Adding to 1221631631 its reverse (1361361221), we get a palindrome (2582992852).

The spelling of 1221631631 in words is "one billion, two hundred twenty-one million, six hundred thirty-one thousand, six hundred thirty-one".