2121965057 has 4 divisors (see below), whose sum is σ = 2135480916. Its totient is φ = 2108449200.

The previous prime is 2121965039. The next prime is 2121965063. The reversal of 2121965057 is 7505691212.

It is a happy number.

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 1098988801 + 1022976256 = 33151^2 + 31984^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121965057 - 2⁶ = 2121964993 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 2121965057.

It is not an unprimeable number, because it can be changed into a prime (2121965017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6757694 + ... + 6758007.

It is an arithmetic number, because the mean of its divisors is an integer number (533870229).

Almost surely, 2^2121965057 is an apocalyptic number.

It is an amenable number.

2121965057 is a deficient number, since it is larger than the sum of its proper divisors (13515859).

2121965057 is a wasteful number, since it uses less digits than its factorization.

2121965057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13515858.

The product of its (nonzero) digits is 37800, while the sum is 38.

The square root of 2121965057 is about 46064.7919456932. The cubic root of 2121965057 is about 1285.0284493593.

The spelling of 2121965057 in words is "two billion, one hundred twenty-one million, nine hundred sixty-five thousand, fifty-seven".