21605871180087 has 12 divisors (see below), whose sum is σ = 31969663047504. Its totient is φ = 14052599141280.

The previous prime is 21605871180083. The next prime is 21605871180121. The reversal of 21605871180087 is 78008117850612.

21605871180087 is a `hidden beast` number, since 21 + 605 + 8 + 7 + 1 + 1 + 8 + 0 + 0 + 8 + 7 = 666.

It is not a de Polignac number, because 21605871180087 - 2² = 21605871180083 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21605871180083) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29276247843 + ... + 29276248580.

It is an arithmetic number, because the mean of its divisors is an integer number (2664138587292).

Almost surely, 2^{21605871180087} is an apocalyptic number.

21605871180087 is a deficient number, since it is larger than the sum of its proper divisors (10363791867417).

21605871180087 is a wasteful number, since it uses less digits than its factorization.

21605871180087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58552496470 (or 58552496467 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 54.

The spelling of 21605871180087 in words is "twenty-one trillion, six hundred five billion, eight hundred seventy-one million, one hundred eighty thousand, eighty-seven".