21913834 has 4 divisors (see below), whose sum is σ = 32870754. Its totient is φ = 10956916.

The previous prime is 21913831. The next prime is 21913849. The reversal of 21913834 is 43831912.

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., 21594609 + 319225 = 4647^2 + 565^2 .

It is a super-2 number, since 2×21913834² = 960432241159112, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21913796 and 21913805.

It is not an unprimeable number, because it can be changed into a prime (21913831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5478457 + ... + 5478460.

Almost surely, 2^21913834 is an apocalyptic number.

21913834 is a deficient number, since it is larger than the sum of its proper divisors (10956920).

21913834 is a wasteful number, since it uses less digits than its factorization.

21913834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10956919.

The product of its digits is 5184, while the sum is 31.

The square root of 21913834 is about 4681.2214218086. The cubic root of 21913834 is about 279.8376354592.

The spelling of 21913834 in words is "twenty-one million, nine hundred thirteen thousand, eight hundred thirty-four".