27997920 has 96 divisors (see below), whose sum is σ = 98007840. Its totient is φ = 7464960.

The previous prime is 27997903. The next prime is 27997943. The reversal of 27997920 is 2979972.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1080 + ... + 7560.

It is an arithmetic number, because the mean of its divisors is an integer number (1020915).

Almost surely, 2^27997920 is an apocalyptic number.

27997920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27997920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49003920).

27997920 is an abundant number, since it is smaller than the sum of its proper divisors (70009920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27997920 is a wasteful number, since it uses less digits than its factorization.

27997920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6505 (or 6491 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 45.

The square root of 27997920 is about 5291.3060769530. The cubic root of 27997920 is about 303.6513778287.

The spelling of 27997920 in words is "twenty-seven million, nine hundred ninety-seven thousand, nine hundred twenty".