21326487 has 32 divisors (see below), whose sum is σ = 35266560. Its totient is φ = 11162880.

The previous prime is 21326479. The next prime is 21326527. The reversal of 21326487 is 78462312.

It is not a de Polignac number, because 21326487 - 2³ = 21326479 is a prime.

It is a super-2 number, since 2×21326487² = 909638095522338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21326477) 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 31 ways as a sum of consecutive naturals, for example, 51939 + ... + 52347.

It is an arithmetic number, because the mean of its divisors is an integer number (1102080).

Almost surely, 2^21326487 is an apocalyptic number.

21326487 is a deficient number, since it is larger than the sum of its proper divisors (13940073).

21326487 is a wasteful number, since it uses less digits than its factorization.

21326487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623.

The product of its digits is 16128, while the sum is 33.

The square root of 21326487 is about 4618.0609567220. The cubic root of 21326487 is about 277.3148379259.

Adding to 21326487 its reverse (78462312), we get a palindrome (99788799).

The spelling of 21326487 in words is "twenty-one million, three hundred twenty-six thousand, four hundred eighty-seven".