2101039981 has 2 divisors, whose sum is σ = 2101039982. Its totient is φ = 2101039980.

The previous prime is 2101039943. The next prime is 2101040033. The reversal of 2101039981 is 1899301012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1411504900 + 689535081 = 37570^2 + 26259^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2101039981 is a prime.

It is a super-2 number, since 2×2101039981² = 8828738003520960722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2101039921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050519990 + 1050519991.

It is an arithmetic number, because the mean of its divisors is an integer number (1050519991).

Almost surely, 2^2101039981 is an apocalyptic number.

It is an amenable number.

2101039981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101039981 is an equidigital number, since it uses as much as digits as its factorization.

2101039981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 2101039981 is about 45837.1026680352. The cubic root of 2101039981 is about 1280.7905234345.

The spelling of 2101039981 in words is "two billion, one hundred one million, thirty-nine thousand, nine hundred eighty-one".