27971863920 has 1280 divisors, whose sum is σ = 137151221760. Its totient is φ = 5042995200.

The previous prime is 27971863891. The next prime is 27971863961. The reversal of 27971863920 is 2936817972.

27971863920 is a `hidden beast` number, since 2 + 79 + 7 + 186 + 392 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 255 ways as a sum of consecutive naturals, for example, 36756340 + ... + 36757100.

It is an arithmetic number, because the mean of its divisors is an integer number (107149392).

Almost surely, 2^27971863920 is an apocalyptic number.

27971863920 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 27971863920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68575610880).

27971863920 is an abundant number, since it is smaller than the sum of its proper divisors (109179357840).

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

27971863920 is a wasteful number, since it uses less digits than its factorization.

27971863920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831 (or 819 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The spelling of 27971863920 in words is "twenty-seven billion, nine hundred seventy-one million, eight hundred sixty-three thousand, nine hundred twenty".