21342973 has 8 divisors (see below), whose sum is σ = 23328000. Its totient is φ = 19439040.

The previous prime is 21342967. The next prime is 21342989. The reversal of 21342973 is 37924312.

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 21342973 - 2¹⁷ = 21211901 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342943) 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, 19723 + ... + 20776.

It is an arithmetic number, because the mean of its divisors is an integer number (2916000).

Almost surely, 2^21342973 is an apocalyptic number.

It is an amenable number.

21342973 is a deficient number, since it is larger than the sum of its proper divisors (1985027).

21342973 is a wasteful number, since it uses less digits than its factorization.

21342973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40547.

The product of its digits is 9072, while the sum is 31.

The square root of 21342973 is about 4619.8455601892. The cubic root of 21342973 is about 277.3862770222.

The spelling of 21342973 in words is "twenty-one million, three hundred forty-two thousand, nine hundred seventy-three".