2135122021 has 4 divisors (see below), whose sum is σ = 2260717452. Its totient is φ = 2009526592.

The previous prime is 2135121997. The next prime is 2135122069. The reversal of 2135122021 is 1202215312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 565773796 + 1569348225 = 23786^2 + 39615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2135122021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2135122021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2135122081) 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, 62797690 + ... + 62797723.

It is an arithmetic number, because the mean of its divisors is an integer number (565179363).

Almost surely, 2^2135122021 is an apocalyptic number.

It is an amenable number.

2135122021 is a deficient number, since it is larger than the sum of its proper divisors (125595431).

2135122021 is a wasteful number, since it uses less digits than its factorization.

2135122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125595430.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 2135122021 is about 46207.3805901179. The cubic root of 2135122021 is about 1287.6788620834.

Adding to 2135122021 its reverse (1202215312), we get a palindrome (3337337333).

The spelling of 2135122021 in words is "two billion, one hundred thirty-five million, one hundred twenty-two thousand, twenty-one".