21394634 has 8 divisors (see below), whose sum is σ = 33198660. Its totient is φ = 10328416.

The previous prime is 21394631. The next prime is 21394673. The reversal of 21394634 is 43649312.

It can be written as a sum of positive squares in 2 ways, for example, as 21187609 + 207025 = 4603^2 + 455^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21394634.

It is not an unprimeable number, because it can be changed into a prime (21394631) 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, 184379 + ... + 184494.

Almost surely, 2^21394634 is an apocalyptic number.

21394634 is a deficient number, since it is larger than the sum of its proper divisors (11804026).

21394634 is a wasteful number, since it uses less digits than its factorization.

21394634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368904.

The product of its digits is 15552, while the sum is 32.

The square root of 21394634 is about 4625.4333851003. The cubic root of 21394634 is about 277.6099026302.

The spelling of 21394634 in words is "twenty-one million, three hundred ninety-four thousand, six hundred thirty-four".