1020199981 has 4 divisors (see below), whose sum is σ = 1025035264. Its totient is φ = 1015364700.

The previous prime is 1020199979. The next prime is 1020200023. The reversal of 1020199981 is 1899910201.

1020199981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1899910201 = 7 ⋅271415743.

It is a cyclic number.

It is not a de Polignac number, because 1020199981 - 2¹ = 1020199979 is a prime.

It is a super-2 number, since 2×1020199981² = 2081616002464800722, 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 (1020196981) 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, 2417325 + ... + 2417746.

It is an arithmetic number, because the mean of its divisors is an integer number (256258816).

Almost surely, 2^1020199981 is an apocalyptic number.

It is an amenable number.

1020199981 is a deficient number, since it is larger than the sum of its proper divisors (4835283).

1020199981 is an equidigital number, since it uses as much as digits as its factorization.

1020199981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4835282.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 1020199981 is about 31940.5695158994. The cubic root of 1020199981 is about 1006.6884913449.

The spelling of 1020199981 in words is "one billion, twenty million, one hundred ninety-nine thousand, nine hundred eighty-one".