1321978033 has 4 divisors (see below), whose sum is σ = 1322614768. Its totient is φ = 1321341300.

The previous prime is 1321977967. The next prime is 1321978037. The reversal of 1321978033 is 3308791231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1321978033 - 2²⁹ = 785107121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1321977983 and 1321978001.

It is not an unprimeable number, because it can be changed into a prime (1321978037) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 315243 + ... + 319408.

It is an arithmetic number, because the mean of its divisors is an integer number (330653692).

Almost surely, 2^1321978033 is an apocalyptic number.

It is an amenable number.

1321978033 is a deficient number, since it is larger than the sum of its proper divisors (636735).

1321978033 is an equidigital number, since it uses as much as digits as its factorization.

1321978033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636734.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 1321978033 is about 36359.0158420164. The cubic root of 1321978033 is about 1097.5089727942.

The spelling of 1321978033 in words is "one billion, three hundred twenty-one million, nine hundred seventy-eight thousand, thirty-three".