21727240625 has 12 divisors (see below), whose sum is σ = 27157316508. Its totient is φ = 17381790000.

The previous prime is 21727240607. The next prime is 21727240637. The reversal of 21727240625 is 52604272712.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 18054759424 + 3672481201 = 134368^2 + 60601^2 .

It is not a de Polignac number, because 21727240625 - 2³² = 17432273329 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3473234 + ... + 3479483.

It is an arithmetic number, because the mean of its divisors is an integer number (2263109709).

Almost surely, 2^21727240625 is an apocalyptic number.

21727240625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21727240625 is a deficient number, since it is larger than the sum of its proper divisors (5430075883).

21727240625 is an frugal number, since it uses more digits than its factorization.

21727240625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6952742 (or 6952722 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 38.

The spelling of 21727240625 in words is "twenty-one billion, seven hundred twenty-seven million, two hundred forty thousand, six hundred twenty-five".