21755234 has 4 divisors (see below), whose sum is σ = 32632854. Its totient is φ = 10877616.

The previous prime is 21755221. The next prime is 21755243. The reversal of 21755234 is 43255712.

It is a happy number.

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., 18088009 + 3667225 = 4253^2 + 1915^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21755197 and 21755206.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5438807 + ... + 5438810.

Almost surely, 2^21755234 is an apocalyptic number.

21755234 is a deficient number, since it is larger than the sum of its proper divisors (10877620).

21755234 is a wasteful number, since it uses less digits than its factorization.

21755234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10877619.

The product of its digits is 8400, while the sum is 29.

The square root of 21755234 is about 4664.2506364903. The cubic root of 21755234 is about 279.1608977596.

The spelling of 21755234 in words is "twenty-one million, seven hundred fifty-five thousand, two hundred thirty-four".