21352879 has 4 divisors (see below), whose sum is σ = 21366184. Its totient is φ = 21339576.

The previous prime is 21352861. The next prime is 21352883. The reversal of 21352879 is 97825312.

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

It is a cyclic number.

It is not a de Polignac number, because 21352879 - 2⁵ = 21352847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353879) 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, 3852 + ... + 7585.

It is an arithmetic number, because the mean of its divisors is an integer number (5341546).

Almost surely, 2^21352879 is an apocalyptic number.

21352879 is a deficient number, since it is larger than the sum of its proper divisors (13305).

21352879 is a wasteful number, since it uses less digits than its factorization.

21352879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13304.

The product of its digits is 30240, while the sum is 37.

The square root of 21352879 is about 4620.9175495782. The cubic root of 21352879 is about 277.4291851877.

The spelling of 21352879 in words is "twenty-one million, three hundred fifty-two thousand, eight hundred seventy-nine".