21225752660 has 48 divisors (see below), whose sum is σ = 50959673856. Its totient is φ = 7274848512.

The previous prime is 21225752633. The next prime is 21225752711. The reversal of 21225752660 is 6625752212.

It is a happy number.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 398144 + ... + 448296.

It is an arithmetic number, because the mean of its divisors is an integer number (1061659872).

Almost surely, 2^21225752660 is an apocalyptic number.

21225752660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21225752660 is an abundant number, since it is smaller than the sum of its proper divisors (29733921196).

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

21225752660 is a wasteful number, since it uses less digits than its factorization.

21225752660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53192 (or 53190 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The spelling of 21225752660 in words is "twenty-one billion, two hundred twenty-five million, seven hundred fifty-two thousand, six hundred sixty".