71636421820 has 24 divisors (see below), whose sum is σ = 150445402128. Its totient is φ = 28652870400.

The previous prime is 71636421817. The next prime is 71636421859. The reversal of 71636421820 is 2812463617.

It is a super-2 number, since 2×71636421820² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 272715 + ... + 466525.

It is an arithmetic number, because the mean of its divisors is an integer number (6268558422).

Almost surely, 2^71636421820 is an apocalyptic number.

It is an amenable number.

71636421820 is an abundant number, since it is smaller than the sum of its proper divisors (78808980308).

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

71636421820 is a wasteful number, since it uses less digits than its factorization.

71636421820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212301 (or 212299 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

The spelling of 71636421820 in words is "seventy-one billion, six hundred thirty-six million, four hundred twenty-one thousand, eight hundred twenty".