21973547 has 8 divisors (see below), whose sum is σ = 22524480. Its totient is φ = 21428680.

The previous prime is 21973529. The next prime is 21973591. The reversal of 21973547 is 74537912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21973547 is a prime.

It is a super-2 number, since 2×21973547² = 965673535522418, 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 21973547.

It is not an unprimeable number, because it can be changed into a prime (21973247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6308 + ... + 9150.

It is an arithmetic number, because the mean of its divisors is an integer number (2815560).

Almost surely, 2^21973547 is an apocalyptic number.

21973547 is a deficient number, since it is larger than the sum of its proper divisors (550933).

21973547 is a wasteful number, since it uses less digits than its factorization.

21973547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3033.

The product of its digits is 52920, while the sum is 38.

The square root of 21973547 is about 4687.5950123704. The cubic root of 21973547 is about 280.0915814372.

The spelling of 21973547 in words is "twenty-one million, nine hundred seventy-three thousand, five hundred forty-seven".