4278591981 has 12 divisors (see below), whose sum is σ = 6180807360. Its totient is φ = 2852109000.

The previous prime is 4278591971. The next prime is 4278591991. The reversal of 4278591981 is 1891958724.

It is a happy number.

4278591981 is a `hidden beast` number, since 42 + 7 + 8 + 591 + 9 + 8 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (4278591971) and next prime (4278591991).

It is not a de Polignac number, because 4278591981 - 2⁵ = 4278591949 is a prime.

It is a super-2 number, since 2×4278591981² = 36612698679755008722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4278591901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 111580 + ... + 144938.

It is an arithmetic number, because the mean of its divisors is an integer number (515067280).

Almost surely, 2^4278591981 is an apocalyptic number.

It is an amenable number.

4278591981 is a deficient number, since it is larger than the sum of its proper divisors (1902215379).

4278591981 is a wasteful number, since it uses less digits than its factorization.

4278591981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47616 (or 47613 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 54.

The square root of 4278591981 is about 65410.9469507972. The cubic root of 4278591981 is about 1623.4302133961.

The spelling of 4278591981 in words is "four billion, two hundred seventy-eight million, five hundred ninety-one thousand, nine hundred eighty-one".