21682217157 has 8 divisors (see below), whose sum is σ = 28910311584. Its totient is φ = 14454467088.

The previous prime is 21682217147. The next prime is 21682217173. The reversal of 21682217157 is 75171228612.

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

It is not a de Polignac number, because 21682217157 - 2⁸ = 21682216901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21682217147) 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, 167778 + ... + 267420.

It is an arithmetic number, because the mean of its divisors is an integer number (3613788948).

Almost surely, 2^21682217157 is an apocalyptic number.

It is an amenable number.

21682217157 is a deficient number, since it is larger than the sum of its proper divisors (7228094427).

21682217157 is an equidigital number, since it uses as much as digits as its factorization.

21682217157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172179.

The product of its digits is 94080, while the sum is 42.

The spelling of 21682217157 in words is "twenty-one billion, six hundred eighty-two million, two hundred seventeen thousand, one hundred fifty-seven".