21961246788 has 72 divisors (see below), whose sum is σ = 61844928600. Its totient is φ = 6524292096.

The previous prime is 21961246771. The next prime is 21961246793. The reversal of 21961246788 is 88764216912.

It is a happy number.

21961246788 is a `hidden beast` number, since 2 + 1 + 96 + 12 + 467 + 88 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3724905024 + 18236341764 = 61032^2 + 135042^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 795493 + ... + 822636.

Almost surely, 2^21961246788 is an apocalyptic number.

It is an amenable number.

21961246788 is an abundant number, since it is smaller than the sum of its proper divisors (39883681812).

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

21961246788 is a wasteful number, since it uses less digits than its factorization.

21961246788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618181 (or 1618176 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 54.

The spelling of 21961246788 in words is "twenty-one billion, nine hundred sixty-one million, two hundred forty-six thousand, seven hundred eighty-eight".