1981353839 has 8 divisors (see below), whose sum is σ = 2110765440. Its totient is φ = 1854455256.

The previous prime is 1981353827. The next prime is 1981353911. The reversal of 1981353839 is 9383531891.

1981353839 = 3372² + 3373² + ... + 3537².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1981353839 is a prime.

It is a super-3 number, since 3×1981353839³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981355839) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 626627 + ... + 629780.

It is an arithmetic number, because the mean of its divisors is an integer number (263845680).

Almost surely, 2^1981353839 is an apocalyptic number.

1981353839 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1981353839 is a deficient number, since it is larger than the sum of its proper divisors (129411601).

1981353839 is a wasteful number, since it uses less digits than its factorization.

1981353839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1256509.

The product of its digits is 699840, while the sum is 50.

The square root of 1981353839 is about 44512.4009574860. The cubic root of 1981353839 is about 1255.9933700054.

The spelling of 1981353839 in words is "one billion, nine hundred eighty-one million, three hundred fifty-three thousand, eight hundred thirty-nine".