21526473 has 16 divisors (see below), whose sum is σ = 29561600. Its totient is φ = 13927680.

The previous prime is 21526469. The next prime is 21526499. The reversal of 21526473 is 37462512.

It is not a de Polignac number, because 21526473 - 2² = 21526469 is a prime.

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 21526473.

It is not an unprimeable number, because it can be changed into a prime (21506473) 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 15 ways as a sum of consecutive naturals, for example, 13713 + ... + 15201.

It is an arithmetic number, because the mean of its divisors is an integer number (1847600).

Almost surely, 2^21526473 is an apocalyptic number.

It is an amenable number.

21526473 is a deficient number, since it is larger than the sum of its proper divisors (8035127).

21526473 is a wasteful number, since it uses less digits than its factorization.

21526473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1632.

The product of its digits is 10080, while the sum is 30.

The square root of 21526473 is about 4639.6630265570. The cubic root of 21526473 is about 278.1789688309.

Adding to 21526473 its reverse (37462512), we get a palindrome (58988985).

The spelling of 21526473 in words is "twenty-one million, five hundred twenty-six thousand, four hundred seventy-three".