2181251968 has 32 divisors (see below), whose sum is σ = 4966245360. Its totient is φ = 934821888.

The previous prime is 2181251951. The next prime is 2181251981. The reversal of 2181251968 is 8691521812.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-3 number, since 3×2181251968³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1216321 + ... + 1218112.

Almost surely, 2^2181251968 is an apocalyptic number.

2181251968 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

2181251968 is an abundant number, since it is smaller than the sum of its proper divisors (2784993392).

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

2181251968 is an equidigital number, since it uses as much as digits as its factorization.

2181251968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2434454 (or 2434442 counting only the distinct ones).

The product of its digits is 69120, while the sum is 43.

The square root of 2181251968 is about 46703.8752995937. The cubic root of 2181251968 is about 1296.8864280663.

The spelling of 2181251968 in words is "two billion, one hundred eighty-one million, two hundred fifty-one thousand, nine hundred sixty-eight".