1321099380 has 72 divisors (see below), whose sum is σ = 4055661792. Its totient is φ = 348044736.

The previous prime is 1321099337. The next prime is 1321099399. The reversal of 1321099380 is 839901231.

1321099380 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29274 + ... + 59153.

It is an arithmetic number, because the mean of its divisors is an integer number (56328636).

Almost surely, 2^1321099380 is an apocalyptic number.

1321099380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321099380 is an abundant number, since it is smaller than the sum of its proper divisors (2734562412).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1321099380 is a wasteful number, since it uses less digits than its factorization.

1321099380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88525 (or 88520 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 1321099380 is about 36346.9308195341. The cubic root of 1321099380 is about 1097.2657657076.

The spelling of 1321099380 in words is "one billion, three hundred twenty-one million, ninety-nine thousand, three hundred eighty".