27721980 has 192 divisors, whose sum is σ = 101606400. Its totient is φ = 6186240.

The previous prime is 27721979. The next prime is 27721997. The reversal of 27721980 is 8912772.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 77041 + ... + 77399.

It is an arithmetic number, because the mean of its divisors is an integer number (529200).

Almost surely, 2^27721980 is an apocalyptic number.

27721980 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 27721980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50803200).

27721980 is an abundant number, since it is smaller than the sum of its proper divisors (73884420).

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

27721980 is a wasteful number, since it uses less digits than its factorization.

27721980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 27721980 is about 5265.1666640288. The cubic root of 27721980 is about 302.6505136271.

The spelling of 27721980 in words is "twenty-seven million, seven hundred twenty-one thousand, nine hundred eighty".