21704115231 has 24 divisors (see below), whose sum is σ = 31832279856. Its totient is φ = 14247653760.

The previous prime is 21704115221. The next prime is 21704115241. The reversal of 21704115231 is 13251140712.

21704115231 is a `hidden beast` number, since 2 + 17 + 0 + 411 + 5 + 231 = 666.

It is an interprime number because it is at equal distance from previous prime (21704115221) and next prime (21704115241).

It is not a de Polignac number, because 21704115231 - 2¹⁰ = 21704114207 is a prime.

It is a super-2 number, since 2×21704115231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21704115195 and 21704115204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21704115211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 375796 + ... + 429686.

It is an arithmetic number, because the mean of its divisors is an integer number (1326344994).

Almost surely, 2^21704115231 is an apocalyptic number.

21704115231 is a deficient number, since it is larger than the sum of its proper divisors (10128164625).

21704115231 is a wasteful number, since it uses less digits than its factorization.

21704115231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54583 (or 54580 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

Adding to 21704115231 its reverse (13251140712), we get a palindrome (34955255943).

The spelling of 21704115231 in words is "twenty-one billion, seven hundred four million, one hundred fifteen thousand, two hundred thirty-one".