7870697721 has 16 divisors (see below), whose sum is σ = 11820025920. Its totient is φ = 5175252000.

The previous prime is 7870697713. The next prime is 7870697729. The reversal of 7870697721 is 1277960787.

It is an interprime number because it is at equal distance from previous prime (7870697713) and next prime (7870697729).

It is not a de Polignac number, because 7870697721 - 2³ = 7870697713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7870697729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1994655 + ... + 1998596.

It is an arithmetic number, because the mean of its divisors is an integer number (738751620).

Almost surely, 2^7870697721 is an apocalyptic number.

It is an amenable number.

7870697721 is a deficient number, since it is larger than the sum of its proper divisors (3949328199).

7870697721 is a wasteful number, since it uses less digits than its factorization.

7870697721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3993333 (or 3993327 counting only the distinct ones).

The product of its (nonzero) digits is 2074464, while the sum is 54.

The square root of 7870697721 is about 88716.9528387895. The cubic root of 7870697721 is about 1989.1662307693.

The spelling of 7870697721 in words is "seven billion, eight hundred seventy million, six hundred ninety-seven thousand, seven hundred twenty-one".