21913634 has 4 divisors (see below), whose sum is σ = 32870454. Its totient is φ = 10956816.

The previous prime is 21913627. The next prime is 21913637. The reversal of 21913634 is 43631912.

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

It can be written as a sum of positive squares in only one way, i.e., 12285025 + 9628609 = 3505^2 + 3103^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21913597 and 21913606.

It is not an unprimeable number, because it can be changed into a prime (21913637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5478407 + ... + 5478410.

Almost surely, 2^21913634 is an apocalyptic number.

21913634 is a deficient number, since it is larger than the sum of its proper divisors (10956820).

21913634 is a wasteful number, since it uses less digits than its factorization.

21913634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10956819.

The product of its digits is 3888, while the sum is 29.

The square root of 21913634 is about 4681.2000598137. The cubic root of 21913634 is about 279.8367841294.

The spelling of 21913634 in words is "twenty-one million, nine hundred thirteen thousand, six hundred thirty-four".