1981916445 has 16 divisors (see below), whose sum is σ = 3238536960. Its totient is φ = 1034531904.

The previous prime is 1981916437. The next prime is 1981916471. The reversal of 1981916445 is 5446191891.

It is not a de Polignac number, because 1981916445 - 2³ = 1981916437 is a prime.

It is a super-2 number, since 2×1981916445² = 7855985589922876050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1981916394 and 1981916403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1404910 + ... + 1406319.

It is an arithmetic number, because the mean of its divisors is an integer number (202408560).

Almost surely, 2^1981916445 is an apocalyptic number.

1981916445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1981916445 is a deficient number, since it is larger than the sum of its proper divisors (1256620515).

1981916445 is a wasteful number, since it uses less digits than its factorization.

1981916445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2811284.

The product of its digits is 311040, while the sum is 48.

The square root of 1981916445 is about 44518.7201635447. The cubic root of 1981916445 is about 1256.1122386496.

The spelling of 1981916445 in words is "one billion, nine hundred eighty-one million, nine hundred sixteen thousand, four hundred forty-five".