21492087 has 4 divisors (see below), whose sum is σ = 28656120. Its totient is φ = 14328056.

The previous prime is 21492067. The next prime is 21492151. The reversal of 21492087 is 78029412.

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 21492087 - 2¹⁹ = 20967799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21492007) 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, 3582012 + ... + 3582017.

It is an arithmetic number, because the mean of its divisors is an integer number (7164030).

Almost surely, 2^21492087 is an apocalyptic number.

21492087 is a deficient number, since it is larger than the sum of its proper divisors (7164033).

21492087 is an equidigital number, since it uses as much as digits as its factorization.

21492087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7164032.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21492087 is about 4635.9558884873. The cubic root of 21492087 is about 278.0307705360.

The spelling of 21492087 in words is "twenty-one million, four hundred ninety-two thousand, eighty-seven".