3981257840 has 60 divisors (see below), whose sum is σ = 10767688056. Its totient is φ = 1365001344.

The previous prime is 3981257803. The next prime is 3981257893. The reversal of 3981257840 is 487521893.

It is a happy number.

3981257840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×3981257840² = 31700827977122931200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 503894 + ... + 511733.

Almost surely, 2^3981257840 is an apocalyptic number.

It is an amenable number.

3981257840 is an abundant number, since it is smaller than the sum of its proper divisors (6786430216).

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

3981257840 is a wasteful number, since it uses less digits than its factorization.

3981257840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015654 (or 1015641 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 47.

The square root of 3981257840 is about 63097.2094470112. The cubic root of 3981257840 is about 1584.9178925646.

The spelling of 3981257840 in words is "three billion, nine hundred eighty-one million, two hundred fifty-seven thousand, eight hundred forty".