1321551215 has 16 divisors (see below), whose sum is σ = 1616308320. Its totient is φ = 1037076480.

The previous prime is 1321551197. The next prime is 1321551223. The reversal of 1321551215 is 5121551231.

It is not a de Polignac number, because 1321551215 - 2¹⁶ = 1321485679 is a prime.

It is a super-2 number, since 2×1321551215² = 3492995227735952450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72551 + ... + 88919.

It is an arithmetic number, because the mean of its divisors is an integer number (101019270).

Almost surely, 2^1321551215 is an apocalyptic number.

1321551215 is a deficient number, since it is larger than the sum of its proper divisors (294757105).

1321551215 is a wasteful number, since it uses less digits than its factorization.

1321551215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16682.

The product of its digits is 1500, while the sum is 26.

The square root of 1321551215 is about 36353.1458748758. The cubic root of 1321551215 is about 1097.3908450099.

The spelling of 1321551215 in words is "one billion, three hundred twenty-one million, five hundred fifty-one thousand, two hundred fifteen".