20680823257646 has 4 divisors (see below), whose sum is σ = 31021234886472. Its totient is φ = 10340411628822.

The previous prime is 20680823257631. The next prime is 20680823257667. The reversal of 20680823257646 is 64675232808602.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×20680823257646² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5170205814410 + ... + 5170205814413.

It is an arithmetic number, because the mean of its divisors is an integer number (7755308721618).

Almost surely, 2^{20680823257646} is an apocalyptic number.

20680823257646 is a deficient number, since it is larger than the sum of its proper divisors (10340411628826).

20680823257646 is a wasteful number, since it uses less digits than its factorization.

20680823257646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10340411628825.

The product of its (nonzero) digits is 46448640, while the sum is 59.

The spelling of 20680823257646 in words is "twenty trillion, six hundred eighty billion, eight hundred twenty-three million, two hundred fifty-seven thousand, six hundred forty-six".