21349689 has 4 divisors (see below), whose sum is σ = 28466256. Its totient is φ = 14233124.

The previous prime is 21349687. The next prime is 21349697. The reversal of 21349689 is 98694312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21349689 - 2¹ = 21349687 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21349689.

It is not an unprimeable number, because it can be changed into a prime (21349687) 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, 3558279 + ... + 3558284.

It is an arithmetic number, because the mean of its divisors is an integer number (7116564).

Almost surely, 2^21349689 is an apocalyptic number.

It is an amenable number.

21349689 is a deficient number, since it is larger than the sum of its proper divisors (7116567).

21349689 is an equidigital number, since it uses as much as digits as its factorization.

21349689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7116566.

The product of its digits is 93312, while the sum is 42.

The square root of 21349689 is about 4620.5723671424. The cubic root of 21349689 is about 277.4153690465.

The spelling of 21349689 in words is "twenty-one million, three hundred forty-nine thousand, six hundred eighty-nine".