2135101981 has 2 divisors, whose sum is σ = 2135101982. Its totient is φ = 2135101980.

The previous prime is 2135101973. The next prime is 2135102033. The reversal of 2135101981 is 1891015312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2049372900 + 85729081 = 45270^2 + 9259^2 .

It is a cyclic number.

It is not a de Polignac number, because 2135101981 - 2³ = 2135101973 is a prime.

It is a super-4 number, since 4×2135101981⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2135101951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1067550990 + 1067550991.

It is an arithmetic number, because the mean of its divisors is an integer number (1067550991).

Almost surely, 2^2135101981 is an apocalyptic number.

It is an amenable number.

2135101981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2135101981 is an equidigital number, since it uses as much as digits as its factorization.

2135101981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 2135101981 is about 46207.1637411343. The cubic root of 2135101981 is about 1287.6748334042.

The spelling of 2135101981 in words is "two billion, one hundred thirty-five million, one hundred one thousand, nine hundred eighty-one".