21926087 has 4 divisors (see below), whose sum is σ = 22436040. Its totient is φ = 21416136.

The previous prime is 21926077. The next prime is 21926123. The reversal of 21926087 is 78062912.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21926087 - 2⁴ = 21926071 is a prime.

It is a super-2 number, since 2×21926087² = 961506582263138, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21926077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254912 + ... + 254997.

It is an arithmetic number, because the mean of its divisors is an integer number (5609010).

Almost surely, 2^21926087 is an apocalyptic number.

21926087 is a deficient number, since it is larger than the sum of its proper divisors (509953).

21926087 is an equidigital number, since it uses as much as digits as its factorization.

21926087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509952.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 21926087 is about 4682.5299785479. The cubic root of 21926087 is about 279.8897823005.

Adding to 21926087 its reverse (78062912), we get a palindrome (99988999).

The spelling of 21926087 in words is "twenty-one million, nine hundred twenty-six thousand, eighty-seven".