21894629 has 4 divisors (see below), whose sum is σ = 21926220. Its totient is φ = 21863040.

The previous prime is 21894617. The next prime is 21894641. The reversal of 21894629 is 92649812.

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

It is an interprime number because it is at equal distance from previous prime (21894617) and next prime (21894641).

It can be written as a sum of positive squares in 2 ways, for example, as 13032100 + 8862529 = 3610^2 + 2977^2 .

It is a cyclic number.

It is not a de Polignac number, because 21894629 - 2⁸ = 21894373 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21894329) 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 3 ways as a sum of consecutive naturals, for example, 14732 + ... + 16149.

It is an arithmetic number, because the mean of its divisors is an integer number (5481555).

Almost surely, 2^21894629 is an apocalyptic number.

It is an amenable number.

21894629 is a deficient number, since it is larger than the sum of its proper divisors (31591).

21894629 is an equidigital number, since it uses as much as digits as its factorization.

21894629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31590.

The product of its digits is 62208, while the sum is 41.

The square root of 21894629 is about 4679.1696913021. The cubic root of 21894629 is about 279.7558628745.

The spelling of 21894629 in words is "twenty-one million, eight hundred ninety-four thousand, six hundred twenty-nine".