27918121840 has 40 divisors (see below), whose sum is σ = 74182439520. Its totient is φ = 9571927296.

The previous prime is 27918121831. The next prime is 27918121843. The reversal of 27918121840 is 4812181972.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27918121843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24926335 + ... + 24927454.

It is an arithmetic number, because the mean of its divisors is an integer number (1854560988).

Almost surely, 2^27918121840 is an apocalyptic number.

27918121840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

27918121840 is an abundant number, since it is smaller than the sum of its proper divisors (46264317680).

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

27918121840 is a wasteful number, since it uses less digits than its factorization.

27918121840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49853809 (or 49853803 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 43.

The spelling of 27918121840 in words is "twenty-seven billion, nine hundred eighteen million, one hundred twenty-one thousand, eight hundred forty".