21956545982 has 24 divisors (see below), whose sum is σ = 39347471856. Its totient is φ = 9000817056.

The previous prime is 21956545979. The next prime is 21956546011. The reversal of 21956545982 is 28954565912.

It is a happy number.

It is a super-2 number, since 2×21956545982² (a number of 21 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 in 11 ways as a sum of consecutive naturals, for example, 1474943 + ... + 1489754.

It is an arithmetic number, because the mean of its divisors is an integer number (1639477994).

Almost surely, 2^21956545982 is an apocalyptic number.

21956545982 is a deficient number, since it is larger than the sum of its proper divisors (17390925874).

21956545982 is a wasteful number, since it uses less digits than its factorization.

21956545982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2964752 (or 2964729 counting only the distinct ones).

The product of its digits is 7776000, while the sum is 56.

The spelling of 21956545982 in words is "twenty-one billion, nine hundred fifty-six million, five hundred forty-five thousand, nine hundred eighty-two".