1921354439 has 4 divisors (see below), whose sum is σ = 1921473960. Its totient is φ = 1921234920.

The previous prime is 1921354403. The next prime is 1921354441. The reversal of 1921354439 is 9344531291.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1921354439 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1921354396 and 1921354405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921354459) 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, 31049 + ... + 69330.

It is an arithmetic number, because the mean of its divisors is an integer number (480368490).

Almost surely, 2^1921354439 is an apocalyptic number.

1921354439 is a deficient number, since it is larger than the sum of its proper divisors (119521).

1921354439 is a wasteful number, since it uses less digits than its factorization.

1921354439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119520.

The product of its digits is 116640, while the sum is 41.

The square root of 1921354439 is about 43833.2572255360. The cubic root of 1921354439 is about 1243.1851945796.

The spelling of 1921354439 in words is "one billion, nine hundred twenty-one million, three hundred fifty-four thousand, four hundred thirty-nine".