21525917749 has 8 divisors (see below), whose sum is σ = 24629761728. Its totient is φ = 18429252000.

The previous prime is 21525917713. The next prime is 21525917753. The reversal of 21525917749 is 94771952512.

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

It is a cyclic number.

It is not a de Polignac number, because 21525917749 - 2¹⁵ = 21525884981 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21525917696 and 21525917705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525911749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1788127 + ... + 1800124.

It is an arithmetic number, because the mean of its divisors is an integer number (3078720216).

Almost surely, 2^21525917749 is an apocalyptic number.

It is an amenable number.

21525917749 is a deficient number, since it is larger than the sum of its proper divisors (3103843979).

21525917749 is an equidigital number, since it uses as much as digits as its factorization.

21525917749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3589115.

The product of its digits is 1587600, while the sum is 52.

The spelling of 21525917749 in words is "twenty-one billion, five hundred twenty-five million, nine hundred seventeen thousand, seven hundred forty-nine".