21710660501 has 4 divisors (see below), whose sum is σ = 21712490604. Its totient is φ = 21708830400.

The previous prime is 21710660443. The next prime is 21710660527. The reversal of 21710660501 is 10506601712.

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 12140734225 + 9569926276 = 110185^2 + 97826^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21710660501 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21710660591) 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, 897140 + ... + 921021.

It is an arithmetic number, because the mean of its divisors is an integer number (5428122651).

Almost surely, 2^21710660501 is an apocalyptic number.

It is an amenable number.

21710660501 is a deficient number, since it is larger than the sum of its proper divisors (1830103).

21710660501 is a wasteful number, since it uses less digits than its factorization.

21710660501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1830102.

The product of its (nonzero) digits is 2520, while the sum is 29.

The spelling of 21710660501 in words is "twenty-one billion, seven hundred ten million, six hundred sixty thousand, five hundred one".