1981962091 has 16 divisors (see below), whose sum is σ = 2115475200. Its totient is φ = 1853504640.

The previous prime is 1981962071. The next prime is 1981962107. The reversal of 1981962091 is 1902691891.

It is not a de Polignac number, because 1981962091 - 2¹⁹ = 1981437803 is a prime.

It is a super-2 number, since 2×1981962091² = 7856347460322184562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981962061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 165105 + ... + 176701.

It is an arithmetic number, because the mean of its divisors is an integer number (132217200).

Almost surely, 2^1981962091 is an apocalyptic number.

1981962091 is a deficient number, since it is larger than the sum of its proper divisors (133513109).

1981962091 is a wasteful number, since it uses less digits than its factorization.

1981962091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11814.

The product of its (nonzero) digits is 69984, while the sum is 46.

The square root of 1981962091 is about 44519.2328213324. The cubic root of 1981962091 is about 1256.1218818512.

The spelling of 1981962091 in words is "one billion, nine hundred eighty-one million, nine hundred sixty-two thousand, ninety-one".