21278313717636 has 24 divisors (see below), whose sum is σ = 49657243597920. Its totient is φ = 7091650535872.

The previous prime is 21278313717581. The next prime is 21278313717659. The reversal of 21278313717636 is 63671731387212.

It is a super-2 number, since 2×21278313717636² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140008806 + ... + 140160701.

It is an arithmetic number, because the mean of its divisors is an integer number (2069051816580).

Almost surely, 2^{21278313717636} is an apocalyptic number.

It is an amenable number.

21278313717636 is an abundant number, since it is smaller than the sum of its proper divisors (28378929880284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21278313717636 is a wasteful number, since it uses less digits than its factorization.

21278313717636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280175843 (or 280175841 counting only the distinct ones).

The product of its digits is 10668672, while the sum is 57.

The spelling of 21278313717636 in words is "twenty-one trillion, two hundred seventy-eight billion, three hundred thirteen million, seven hundred seventeen thousand, six hundred thirty-six".