21959591828 has 6 divisors (see below), whose sum is σ = 38429285706. Its totient is φ = 10979795912.

The previous prime is 21959591827. The next prime is 21959591837. The reversal of 21959591828 is 82819595912.

It can be written as a sum of positive squares in only one way, i.e., 21706718224 + 252873604 = 147332^2 + 15902^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21959591827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2744948975 + ... + 2744948982.

It is an arithmetic number, because the mean of its divisors is an integer number (6404880951).

Almost surely, 2^21959591828 is an apocalyptic number.

It is an amenable number.

21959591828 is a deficient number, since it is larger than the sum of its proper divisors (16469693878).

21959591828 is a wasteful number, since it uses less digits than its factorization.

21959591828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5489897961 (or 5489897959 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 59.

The spelling of 21959591828 in words is "twenty-one billion, nine hundred fifty-nine million, five hundred ninety-one thousand, eight hundred twenty-eight".