1321976881 has 9 divisors (see below), whose sum is σ = 1338728619. Its totient is φ = 1305433536.

The previous prime is 1321976879. The next prime is 1321976891. The reversal of 1321976881 is 1886791231.

It is a happy number.

The square root of 1321976881 is 36359.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 537080625 + 784896256 = 23175^2 + 28016^2 .

It is not a de Polignac number, because 1321976881 - 2¹ = 1321976879 is a prime.

It is a super-2 number, since 2×1321976881² = 3495245747796976322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321976891) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3744801 + ... + 3745153.

Almost surely, 2^1321976881 is an apocalyptic number.

1321976881 is the 36359-th square number.

1321976881 is the 18180-th centered octagonal number.

It is an amenable number.

1321976881 is a deficient number, since it is larger than the sum of its proper divisors (16751738).

1321976881 is an frugal number, since it uses more digits than its factorization.

1321976881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912 (or 456 counting only the distinct ones).

The product of its digits is 145152, while the sum is 46.

The cubic root of 1321976881 is about 1097.5086539964.

It can be divided in two parts, 13219 and 76881, that added together give a triangular number (90100 = T₄₂₄).

The spelling of 1321976881 in words is "one billion, three hundred twenty-one million, nine hundred seventy-six thousand, eight hundred eighty-one".