21313669 has 4 divisors (see below), whose sum is σ = 22953196. Its totient is φ = 19674144.

The previous prime is 21313657. The next prime is 21313673. The reversal of 21313669 is 96631312.

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 7896100 + 13417569 = 2810^2 + 3663^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313669 - 2⁷ = 21313541 is a prime.

It is a super-2 number, since 2×21313669² = 908544972483122, which contains 22 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 21313669.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313609) 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, 819744 + ... + 819769.

It is an arithmetic number, because the mean of its divisors is an integer number (5738299).

Almost surely, 2^21313669 is an apocalyptic number.

It is an amenable number.

21313669 is a deficient number, since it is larger than the sum of its proper divisors (1639527).

21313669 is a wasteful number, since it uses less digits than its factorization.

21313669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1639526.

The product of its digits is 5832, while the sum is 31.

The square root of 21313669 is about 4616.6729362172. The cubic root of 21313669 is about 277.2592679988.

The spelling of 21313669 in words is "twenty-one million, three hundred thirteen thousand, six hundred sixty-nine".