21717867051771 has 16 divisors (see below), whose sum is σ = 31607645208960. Its totient is φ = 13154835165120.

The previous prime is 21717867051763. The next prime is 21717867051773. The reversal of 21717867051771 is 17715076871712.

It is not a de Polignac number, because 21717867051771 - 2³ = 21717867051763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21717867051773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 187653841 + ... + 187769538.

It is an arithmetic number, because the mean of its divisors is an integer number (1975477825560).

Almost surely, 2^{21717867051771} is an apocalyptic number.

21717867051771 is a deficient number, since it is larger than the sum of its proper divisors (9889778157189).

21717867051771 is a wasteful number, since it uses less digits than its factorization.

21717867051771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375425146.

The product of its (nonzero) digits is 8067360, while the sum is 60.

The spelling of 21717867051771 in words is "twenty-one trillion, seven hundred seventeen billion, eight hundred sixty-seven million, fifty-one thousand, seven hundred seventy-one".