1321200019 has 4 divisors (see below), whose sum is σ = 1329949840. Its totient is φ = 1312450200.

The previous prime is 1321199977. The next prime is 1321200047. The reversal of 1321200019 is 9100021231.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1321200019 - 2¹¹ = 1321197971 is a prime.

It is a super-2 number, since 2×1321200019² = 3491138980411200722, 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 = 1321199969 and 1321200005.

It is not an unprimeable number, because it can be changed into a prime (1321200079) 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, 4374684 + ... + 4374985.

It is an arithmetic number, because the mean of its divisors is an integer number (332487460).

Almost surely, 2^1321200019 is an apocalyptic number.

1321200019 is a deficient number, since it is larger than the sum of its proper divisors (8749821).

1321200019 is an equidigital number, since it uses as much as digits as its factorization.

1321200019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8749820.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 1321200019 is about 36348.3152154264. The cubic root of 1321200019 is about 1097.2936275846.

The spelling of 1321200019 in words is "one billion, three hundred twenty-one million, two hundred thousand, nineteen".