21555134 has 4 divisors (see below), whose sum is σ = 32332704. Its totient is φ = 10777566.

The previous prime is 21555113. The next prime is 21555179. The reversal of 21555134 is 43155512.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5388782 + ... + 5388785.

It is an arithmetic number, because the mean of its divisors is an integer number (8083176).

Almost surely, 2^21555134 is an apocalyptic number.

21555134 is a deficient number, since it is larger than the sum of its proper divisors (10777570).

21555134 is a wasteful number, since it uses less digits than its factorization.

21555134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10777569.

The product of its digits is 3000, while the sum is 26.

The square root of 21555134 is about 4642.7506932852. The cubic root of 21555134 is about 278.3023727220.

The spelling of 21555134 in words is "twenty-one million, five hundred fifty-five thousand, one hundred thirty-four".