711521021021 has 4 divisors (see below), whose sum is σ = 711542137500. Its totient is φ = 711499904544.

The previous prime is 711521020993. The next prime is 711521021047. The reversal of 711521021021 is 120120125117.

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 414882844996 + 296638176025 = 644114^2 + 544645^2 .

It is a cyclic number.

It is not a de Polignac number, because 711521021021 - 2¹⁸ = 711520758877 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 (711521021051) 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, 10507616 + ... + 10575113.

It is an arithmetic number, because the mean of its divisors is an integer number (177885534375).

Almost surely, 2^711521021021 is an apocalyptic number.

It is an amenable number.

711521021021 is a deficient number, since it is larger than the sum of its proper divisors (21116479).

711521021021 is a wasteful number, since it uses less digits than its factorization.

711521021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21116478.

The product of its (nonzero) digits is 280, while the sum is 23.

Adding to 711521021021 its reverse (120120125117), we get a palindrome (831641146138).

The spelling of 711521021021 in words is "seven hundred eleven billion, five hundred twenty-one million, twenty-one thousand, twenty-one".