21247377722 has 24 divisors (see below), whose sum is σ = 33669465300. Its totient is φ = 10054767168.

The previous prime is 21247377691. The next prime is 21247377727. The reversal of 21247377722 is 22777374212.

It can be written as a sum of positive squares in 2 ways, for example, as 21065909881 + 181467841 = 145141^2 + 13471^2 .

It is a super-2 number, since 2×21247377722² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21247377727) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 758054 + ... + 785582.

Almost surely, 2^21247377722 is an apocalyptic number.

21247377722 is a deficient number, since it is larger than the sum of its proper divisors (12422087578).

21247377722 is a wasteful number, since it uses less digits than its factorization.

21247377722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28638 (or 28619 counting only the distinct ones).

The product of its digits is 460992, while the sum is 44.

The spelling of 21247377722 in words is "twenty-one billion, two hundred forty-seven million, three hundred seventy-seven thousand, seven hundred twenty-two".