21173465 has 8 divisors (see below), whose sum is σ = 26227968. Its totient is φ = 16392240.

The previous prime is 21173437. The next prime is 21173473. The reversal of 21173465 is 56437112.

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

It is not a de Polignac number, because 21173465 - 2¹⁶ = 21107929 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68147 + ... + 68456.

It is an arithmetic number, because the mean of its divisors is an integer number (3278496).

Almost surely, 2^21173465 is an apocalyptic number.

It is an amenable number.

21173465 is a deficient number, since it is larger than the sum of its proper divisors (5054503).

21173465 is a wasteful number, since it uses less digits than its factorization.

21173465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136639.

The product of its digits is 5040, while the sum is 29.

The square root of 21173465 is about 4601.4633541951. The cubic root of 21173465 is about 276.6499812521.

The spelling of 21173465 in words is "twenty-one million, one hundred seventy-three thousand, four hundred sixty-five".