1944821387 has 4 divisors (see below), whose sum is σ = 1945172880. Its totient is φ = 1944469896.

The previous prime is 1944821381. The next prime is 1944821423. The reversal of 1944821387 is 7831284491.

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 1944821387 - 2⁴ = 1944821371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1944821381) 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, 167312 + ... + 178557.

It is an arithmetic number, because the mean of its divisors is an integer number (486293220).

Almost surely, 2^1944821387 is an apocalyptic number.

1944821387 is a deficient number, since it is larger than the sum of its proper divisors (351493).

1944821387 is an equidigital number, since it uses as much as digits as its factorization.

1944821387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351492.

The product of its digits is 387072, while the sum is 47.

The square root of 1944821387 is about 44100.1291041194. The cubic root of 1944821387 is about 1248.2260462213.

The spelling of 1944821387 in words is "one billion, nine hundred forty-four million, eight hundred twenty-one thousand, three hundred eighty-seven".