21474917 has 4 divisors (see below), whose sum is σ = 21586380. Its totient is φ = 21363456.

The previous prime is 21474913. The next prime is 21474919. The reversal of 21474917 is 71947412.

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 5080516 + 16394401 = 2254^2 + 4049^2 .

It is a cyclic number.

It is not a de Polignac number, because 21474917 - 2² = 21474913 is a prime.

It is a super-2 number, since 2×21474917² = 922344120313778, which 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 (21474913) 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, 55442 + ... + 55827.

It is an arithmetic number, because the mean of its divisors is an integer number (5396595).

Almost surely, 2^21474917 is an apocalyptic number.

It is an amenable number.

21474917 is a deficient number, since it is larger than the sum of its proper divisors (111463).

21474917 is a wasteful number, since it uses less digits than its factorization.

21474917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111462.

The product of its digits is 14112, while the sum is 35.

The square root of 21474917 is about 4634.1036889565. The cubic root of 21474917 is about 277.9567113384.

The spelling of 21474917 in words is "twenty-one million, four hundred seventy-four thousand, nine hundred seventeen".