21474547 has 4 divisors (see below), whose sum is σ = 21496840. Its totient is φ = 21452256.

The previous prime is 21474533. The next prime is 21474559. The reversal of 21474547 is 74547412.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21474547 is a prime.

It is a super-2 number, since 2×21474547² = 922312337710418, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21474517) 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, 9633 + ... + 11650.

It is an arithmetic number, because the mean of its divisors is an integer number (5374210).

Almost surely, 2^21474547 is an apocalyptic number.

21474547 is a deficient number, since it is larger than the sum of its proper divisors (22293).

21474547 is a wasteful number, since it uses less digits than its factorization.

21474547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22292.

The product of its digits is 31360, while the sum is 34.

The square root of 21474547 is about 4634.0637673645. The cubic root of 21474547 is about 277.9551149865.

The spelling of 21474547 in words is "twenty-one million, four hundred seventy-four thousand, five hundred forty-seven".