3961321440 has 48 divisors (see below), whose sum is σ = 12478164048. Its totient is φ = 1056352256.

The previous prime is 3961321423. The next prime is 3961321447. The reversal of 3961321440 is 441231693.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3961321447) 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, 4125897 + ... + 4126856.

It is an arithmetic number, because the mean of its divisors is an integer number (259961751).

Almost surely, 2^3961321440 is an apocalyptic number.

3961321440 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3961321440 is an abundant number, since it is smaller than the sum of its proper divisors (8516842608).

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

3961321440 is a wasteful number, since it uses less digits than its factorization.

3961321440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8252771 (or 8252763 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 3961321440 is about 62939.0295444726. The cubic root of 3961321440 is about 1582.2679388884.

The spelling of 3961321440 in words is "three billion, nine hundred sixty-one million, three hundred twenty-one thousand, four hundred forty".