7899961 has 4 divisors (see below), whose sum is σ = 7906852. Its totient is φ = 7893072.

The previous prime is 7899949. The next prime is 7899967. The reversal of 7899961 is 1699987.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6471936 + 1428025 = 2544^2 + 1195^2 .

It is a cyclic number.

It is not a de Polignac number, because 7899961 - 2⁵ = 7899929 is a prime.

It is a Duffinian number.

7899961 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7899967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1266 + ... + 4171.

It is an arithmetic number, because the mean of its divisors is an integer number (1976713).

Almost surely, 2^7899961 is an apocalyptic number.

It is an amenable number.

7899961 is a deficient number, since it is larger than the sum of its proper divisors (6891).

7899961 is a wasteful number, since it uses less digits than its factorization.

7899961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6890.

The product of its digits is 244944, while the sum is 49.

The square root of 7899961 is about 2810.6869267138. The cubic root of 7899961 is about 199.1628423916.

The spelling of 7899961 in words is "seven million, eight hundred ninety-nine thousand, nine hundred sixty-one".