1216901531 has 8 divisors (see below), whose sum is σ = 1356299280. Its totient is φ = 1085038848.

The previous prime is 1216901507. The next prime is 1216901537. The reversal of 1216901531 is 1351096121.

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 1216901531 - 2³⁰ = 143159707 is a prime.

It is a super-2 number, since 2×1216901531² = 2961698672300287922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1216901494 and 1216901503.

It is not an unprimeable number, because it can be changed into a prime (1216901537) 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 7 ways as a sum of consecutive naturals, for example, 1883426 + ... + 1884071.

It is an arithmetic number, because the mean of its divisors is an integer number (169537410).

Almost surely, 2^1216901531 is an apocalyptic number.

1216901531 is a deficient number, since it is larger than the sum of its proper divisors (139397749).

1216901531 is a wasteful number, since it uses less digits than its factorization.

1216901531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3767533.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 1216901531 is about 34884.1157405487. The cubic root of 1216901531 is about 1067.6243713905.

Adding to 1216901531 its reverse (1351096121), we get a palindrome (2567997652).

The spelling of 1216901531 in words is "one billion, two hundred sixteen million, nine hundred one thousand, five hundred thirty-one".