1984069981 has 4 divisors (see below), whose sum is σ = 2037693532. Its totient is φ = 1930446432.

The previous prime is 1984069973. The next prime is 1984070021. The reversal of 1984069981 is 1899604891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1899604891 = 23 ⋅82591517.

It can be written as a sum of positive squares in 2 ways, for example, as 1273847481 + 710222500 = 35691^2 + 26650^2 .

It is a cyclic number.

It is not a de Polignac number, because 1984069981 - 2³ = 1984069973 is a prime.

It is a super-2 number, since 2×1984069981² = 7873067379010680722, which contains 22 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 (1984069921) 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, 26811720 + ... + 26811793.

It is an arithmetic number, because the mean of its divisors is an integer number (509423383).

Almost surely, 2^1984069981 is an apocalyptic number.

It is an amenable number.

1984069981 is a deficient number, since it is larger than the sum of its proper divisors (53623551).

1984069981 is an equidigital number, since it uses as much as digits as its factorization.

1984069981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53623550.

The product of its (nonzero) digits is 1119744, while the sum is 55.

The square root of 1984069981 is about 44542.9004556282. The cubic root of 1984069981 is about 1256.5670347721.

The spelling of 1984069981 in words is "one billion, nine hundred eighty-four million, sixty-nine thousand, nine hundred eighty-one".