21987546722 has 8 divisors (see below), whose sum is σ = 32983996716. Its totient is φ = 10992881152.

The previous prime is 21987546661. The next prime is 21987546733. The reversal of 21987546722 is 22764578912.

It can be written as a sum of positive squares in 2 ways, for example, as 21880030561 + 107516161 = 147919^2 + 10369^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 414863 + ... + 464850.

Almost surely, 2^21987546722 is an apocalyptic number.

21987546722 is a deficient number, since it is larger than the sum of its proper divisors (10996449994).

21987546722 is a wasteful number, since it uses less digits than its factorization.

21987546722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892212.

The product of its digits is 3386880, while the sum is 53.

The spelling of 21987546722 in words is "twenty-one billion, nine hundred eighty-seven million, five hundred forty-six thousand, seven hundred twenty-two".