21519617671 has 8 divisors (see below), whose sum is σ = 22836232800. Its totient is φ = 20208642048.

The previous prime is 21519617657. The next prime is 21519617711. The reversal of 21519617671 is 17671691512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21519617671 - 2¹⁵ = 21519584903 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 (21519617611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1402011 + ... + 1417276.

It is an arithmetic number, because the mean of its divisors is an integer number (2854529100).

Almost surely, 2^21519617671 is an apocalyptic number.

21519617671 is a deficient number, since it is larger than the sum of its proper divisors (1316615129).

21519617671 is a wasteful number, since it uses less digits than its factorization.

21519617671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2819753.

The product of its digits is 158760, while the sum is 46.

The spelling of 21519617671 in words is "twenty-one billion, five hundred nineteen million, six hundred seventeen thousand, six hundred seventy-one".