27720165 has 32 divisors (see below), whose sum is σ = 49522176. Its totient is φ = 13124160.

The previous prime is 27720151. The next prime is 27720167. The reversal of 27720165 is 56102772.

It is not a de Polignac number, because 27720165 - 2⁶ = 27720101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27720167) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5142 + ... + 9048.

It is an arithmetic number, because the mean of its divisors is an integer number (1547568).

Almost surely, 2^27720165 is an apocalyptic number.

It is an amenable number.

27720165 is a deficient number, since it is larger than the sum of its proper divisors (21802011).

27720165 is a wasteful number, since it uses less digits than its factorization.

27720165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3969.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 27720165 is about 5264.9943019912. The cubic root of 27720165 is about 302.6439084872.

It can be divided in two parts, 27720 and 165, that multiplied together give a triangular number (4573800 = T₃₀₂₄).

The spelling of 27720165 in words is "twenty-seven million, seven hundred twenty thousand, one hundred sixty-five".