27561989 has 24 divisors (see below), whose sum is σ = 35844480. Its totient is φ = 20634912.

The previous prime is 27561983. The next prime is 27561997. The reversal of 27561989 is 98916572.

It is not a de Polignac number, because 27561989 - 2⁴ = 27561973 is a prime.

It is a super-2 number, since 2×27561989² = 1519326475272242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27561983) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32432 + ... + 33270.

It is an arithmetic number, because the mean of its divisors is an integer number (1493520).

Almost surely, 2^27561989 is an apocalyptic number.

It is an amenable number.

27561989 is a deficient number, since it is larger than the sum of its proper divisors (8282491).

27561989 is a wasteful number, since it uses less digits than its factorization.

27561989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897 (or 878 counting only the distinct ones).

The product of its digits is 272160, while the sum is 47.

The square root of 27561989 is about 5249.9513331078. The cubic root of 27561989 is about 302.0671641328.

The spelling of 27561989 in words is "twenty-seven million, five hundred sixty-one thousand, nine hundred eighty-nine".