52121061721 has 4 divisors (see below), whose sum is σ = 52137206500. Its totient is φ = 52104916944.

The previous prime is 52121061697. The next prime is 52121061743. The reversal of 52121061721 is 12716012125.

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 16573730121 + 35547331600 = 128739^2 + 188540^2 .

It is a cyclic number.

It is not a de Polignac number, because 52121061721 - 2⁵ = 52121061689 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 52121061721.

It is not an unprimeable number, because it can be changed into a prime (52121061791) 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, 8067546 + ... + 8074003.

It is an arithmetic number, because the mean of its divisors is an integer number (13034301625).

Almost surely, 2^52121061721 is an apocalyptic number.

It is an amenable number.

52121061721 is a deficient number, since it is larger than the sum of its proper divisors (16144779).

52121061721 is a wasteful number, since it uses less digits than its factorization.

52121061721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16144778.

The product of its (nonzero) digits is 1680, while the sum is 28.

Adding to 52121061721 its reverse (12716012125), we get a palindrome (64837073846).

The spelling of 52121061721 in words is "fifty-two billion, one hundred twenty-one million, sixty-one thousand, seven hundred twenty-one".