7881521407 has 2 divisors, whose sum is σ = 7881521408. Its totient is φ = 7881521406.

The previous prime is 7881521399. The next prime is 7881521447. The reversal of 7881521407 is 7041251887.

7881521407 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (7041251887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7881521407 - 2³ = 7881521399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7881521447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3940760703 + 3940760704.

It is an arithmetic number, because the mean of its divisors is an integer number (3940760704).

Almost surely, 2^7881521407 is an apocalyptic number.

7881521407 is a deficient number, since it is larger than the sum of its proper divisors (1).

7881521407 is an equidigital number, since it uses as much as digits as its factorization.

7881521407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 125440, while the sum is 43.

The square root of 7881521407 is about 88777.9331084026. The cubic root of 7881521407 is about 1990.0776386972.

The spelling of 7881521407 in words is "seven billion, eight hundred eighty-one million, five hundred twenty-one thousand, four hundred seven".