16721532523461 has 4 divisors (see below), whose sum is σ = 22295376697952. Its totient is φ = 11147688348972.

The previous prime is 16721532523459. The next prime is 16721532523471. The reversal of 16721532523461 is 16432523512761.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16721532523461 - 2¹ = 16721532523459 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 16721532523461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16721532523441) 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, 2786922087241 + ... + 2786922087246.

It is an arithmetic number, because the mean of its divisors is an integer number (5573844174488).

Almost surely, 2^{16721532523461} is an apocalyptic number.

It is an amenable number.

16721532523461 is a deficient number, since it is larger than the sum of its proper divisors (5573844174491).

16721532523461 is an equidigital number, since it uses as much as digits as its factorization.

16721532523461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5573844174490.

The product of its digits is 1814400, while the sum is 48.

The spelling of 16721532523461 in words is "sixteen trillion, seven hundred twenty-one billion, five hundred thirty-two million, five hundred twenty-three thousand, four hundred sixty-one".