21473237 has 8 divisors (see below), whose sum is σ = 22475904. Its totient is φ = 20476368.

The previous prime is 21473233. The next prime is 21473239. The reversal of 21473237 is 73237412.

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

It is a cyclic number.

It is not a de Polignac number, because 21473237 - 2² = 21473233 is a prime.

It is a super-2 number, since 2×21473237² = 922199814516338, 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 (21473233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7328 + ... + 9830.

It is an arithmetic number, because the mean of its divisors is an integer number (2809488).

Almost surely, 2^21473237 is an apocalyptic number.

It is an amenable number.

21473237 is a deficient number, since it is larger than the sum of its proper divisors (1002667).

21473237 is a wasteful number, since it uses less digits than its factorization.

21473237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2899.

The product of its digits is 7056, while the sum is 29.

The square root of 21473237 is about 4633.9224205850. The cubic root of 21473237 is about 277.9494628905.

The spelling of 21473237 in words is "twenty-one million, four hundred seventy-three thousand, two hundred thirty-seven".