21425753 has 4 divisors (see below), whose sum is σ = 21569700. Its totient is φ = 21281808.

The previous prime is 21425707. The next prime is 21425759. The reversal of 21425753 is 35752412.

It is a happy number.

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 1247689 + 20178064 = 1117^2 + 4492^2 .

It is a cyclic number.

It is not a de Polignac number, because 21425753 - 2⁶ = 21425689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21425759) 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, 71750 + ... + 72047.

It is an arithmetic number, because the mean of its divisors is an integer number (5392425).

Almost surely, 2^21425753 is an apocalyptic number.

It is an amenable number.

21425753 is a deficient number, since it is larger than the sum of its proper divisors (143947).

21425753 is a wasteful number, since it uses less digits than its factorization.

21425753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143946.

The product of its digits is 8400, while the sum is 29.

The square root of 21425753 is about 4628.7960637730. The cubic root of 21425753 is about 277.7444341429.

The spelling of 21425753 in words is "twenty-one million, four hundred twenty-five thousand, seven hundred fifty-three".