21425214509 has 4 divisors (see below), whose sum is σ = 21621776220. Its totient is φ = 21228652800.

The previous prime is 21425214493. The next prime is 21425214527. The reversal of 21425214509 is 90541252412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19327116484 + 2098098025 = 139022^2 + 45805^2 .

It is a cyclic number.

It is not a de Polignac number, because 21425214509 - 2⁴ = 21425214493 is a prime.

It is a super-2 number, since 2×21425214509² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21425214589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98280692 + ... + 98280909.

It is an arithmetic number, because the mean of its divisors is an integer number (5405444055).

Almost surely, 2^21425214509 is an apocalyptic number.

It is an amenable number.

21425214509 is a deficient number, since it is larger than the sum of its proper divisors (196561711).

21425214509 is a wasteful number, since it uses less digits than its factorization.

21425214509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196561710.

The product of its (nonzero) digits is 28800, while the sum is 35.

The spelling of 21425214509 in words is "twenty-one billion, four hundred twenty-five million, two hundred fourteen thousand, five hundred nine".