27721538 has 16 divisors (see below), whose sum is σ = 44874816. Its totient is φ = 12767760.

The previous prime is 27721487. The next prime is 27721567. The reversal of 27721538 is 83512772.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 27721498 and 27721507.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17195 + ... + 18737.

It is an arithmetic number, because the mean of its divisors is an integer number (2804676).

Almost surely, 2^27721538 is an apocalyptic number.

27721538 is a deficient number, since it is larger than the sum of its proper divisors (17153278).

27721538 is a wasteful number, since it uses less digits than its factorization.

27721538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2249.

The product of its digits is 23520, while the sum is 35.

The square root of 27721538 is about 5265.1246898815. The cubic root of 27721538 is about 302.6489051292.

The spelling of 27721538 in words is "twenty-seven million, seven hundred twenty-one thousand, five hundred thirty-eight".