21242521465 has 8 divisors (see below), whose sum is σ = 27808391808. Its totient is φ = 15449106480.

The previous prime is 21242521463. The next prime is 21242521501. The reversal of 21242521465 is 56412524212.

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

It is not a de Polignac number, because 21242521465 - 2¹ = 21242521463 is a prime.

It is a super-4 number, since 4×21242521465⁴ (a number of 42 digits) contains 4444 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21242521465.

It is not an unprimeable number, because it can be changed into a prime (21242521463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193113777 + ... + 193113886.

It is an arithmetic number, because the mean of its divisors is an integer number (3476048976).

Almost surely, 2^21242521465 is an apocalyptic number.

It is an amenable number.

21242521465 is a deficient number, since it is larger than the sum of its proper divisors (6565870343).

21242521465 is a wasteful number, since it uses less digits than its factorization.

21242521465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386227679.

The product of its digits is 38400, while the sum is 34.

The spelling of 21242521465 in words is "twenty-one billion, two hundred forty-two million, five hundred twenty-one thousand, four hundred sixty-five".