2121100061 has 4 divisors (see below), whose sum is σ = 2139870972. Its totient is φ = 2102329152.

The previous prime is 2121100021. The next prime is 2121100097. The reversal of 2121100061 is 1600011212.

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 571496836 + 1549603225 = 23906^2 + 39365^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121100061 - 2³⁰ = 1047358237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121100021) 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, 9385286 + ... + 9385511.

It is an arithmetic number, because the mean of its divisors is an integer number (534967743).

Almost surely, 2^2121100061 is an apocalyptic number.

It is an amenable number.

2121100061 is a deficient number, since it is larger than the sum of its proper divisors (18770911).

2121100061 is a wasteful number, since it uses less digits than its factorization.

2121100061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18770910.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 2121100061 is about 46055.4020827090. The cubic root of 2121100061 is about 1284.8538163329.

Adding to 2121100061 its reverse (1600011212), we get a palindrome (3721111273).

The spelling of 2121100061 in words is "two billion, one hundred twenty-one million, one hundred thousand, sixty-one".