800121861 has 128 divisors (see below), whose sum is σ = 1598054400. Its totient is φ = 383201280.

The previous prime is 800121859. The next prime is 800121869. The reversal of 800121861 is 168121008.

It is not a de Polignac number, because 800121861 - 2¹ = 800121859 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (800121869) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1386405 + ... + 1386981.

It is an arithmetic number, because the mean of its divisors is an integer number (12484800).

Almost surely, 2^800121861 is an apocalyptic number.

It is an amenable number.

800121861 is a deficient number, since it is larger than the sum of its proper divisors (797932539).

800121861 is a wasteful number, since it uses less digits than its factorization.

800121861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 800121861 is about 28286.4253839187. The cubic root of 800121861 is about 928.3649000508.

Adding to 800121861 its reverse (168121008), we get a palindrome (968242869).

The spelling of 800121861 in words is "eight hundred million, one hundred twenty-one thousand, eight hundred sixty-one".