21473507 has 6 divisors (see below), whose sum is σ = 23603244. Its totient is φ = 19521260.

The previous prime is 21473497. The next prime is 21473527. The reversal of 21473507 is 70537412.

It is not a de Polignac number, because 21473507 - 2¹⁰ = 21472483 is a prime.

It is a super-2 number, since 2×21473507² = 922223005758098, 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 21473507.

It is not an unprimeable number, because it can be changed into a prime (21473527) 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 5 ways as a sum of consecutive naturals, for example, 88613 + ... + 88854.

It is an arithmetic number, because the mean of its divisors is an integer number (3933874).

Almost surely, 2^21473507 is an apocalyptic number.

21473507 is a deficient number, since it is larger than the sum of its proper divisors (2129737).

21473507 is a wasteful number, since it uses less digits than its factorization.

21473507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177489 (or 177478 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 21473507 is about 4633.9515534800. The cubic root of 21473507 is about 277.9506278452.

The spelling of 21473507 in words is "twenty-one million, four hundred seventy-three thousand, five hundred seven".