1221432531 has 8 divisors (see below), whose sum is σ = 1776629184. Its totient is φ = 740262120.

The previous prime is 1221432523. The next prime is 1221432631. The reversal of 1221432531 is 1352341221.

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

It is not a de Polignac number, because 1221432531 - 2³ = 1221432523 is a prime.

It is a super-2 number, since 2×1221432531² = 2983794855570131922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221432431) 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, 18506521 + ... + 18506586.

It is an arithmetic number, because the mean of its divisors is an integer number (222078648).

Almost surely, 2^1221432531 is an apocalyptic number.

1221432531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221432531 is a deficient number, since it is larger than the sum of its proper divisors (555196653).

1221432531 is a wasteful number, since it uses less digits than its factorization.

1221432531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37013121.

The product of its digits is 1440, while the sum is 24.

The square root of 1221432531 is about 34948.9989985407. The cubic root of 1221432531 is about 1068.9477911417.

Adding to 1221432531 its reverse (1352341221), we get a palindrome (2573773752).

The spelling of 1221432531 in words is "one billion, two hundred twenty-one million, four hundred thirty-two thousand, five hundred thirty-one".