8000420861 has 4 divisors (see below), whose sum is σ = 8151372252. Its totient is φ = 7849469472.

The previous prime is 8000420833. The next prime is 8000420893. The reversal of 8000420861 is 1680240008.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3456852025 + 4543568836 = 58795^2 + 67406^2 .

It is a cyclic number.

It is not a de Polignac number, because 8000420861 - 2⁶ = 8000420797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8000420261) 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, 75475616 + ... + 75475721.

It is an arithmetic number, because the mean of its divisors is an integer number (2037843063).

Almost surely, 2^8000420861 is an apocalyptic number.

It is an amenable number.

8000420861 is a deficient number, since it is larger than the sum of its proper divisors (150951391).

8000420861 is a wasteful number, since it uses less digits than its factorization.

8000420861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150951390.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 8000420861 is about 89445.0717535628. The cubic root of 8000420861 is about 2000.0350711350.

Adding to 8000420861 its reverse (1680240008), we get a palindrome (9680660869).

The spelling of 8000420861 in words is "eight billion, four hundred twenty thousand, eight hundred sixty-one".