851021129 has 4 divisors (see below), whose sum is σ = 972595584. Its totient is φ = 729446676.

The previous prime is 851021117. The next prime is 851021131. The reversal of 851021129 is 921120158.

851021129 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 851021129 - 2⁴ = 851021113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (851021179) 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, 60787217 + ... + 60787230.

It is an arithmetic number, because the mean of its divisors is an integer number (243148896).

Almost surely, 2^851021129 is an apocalyptic number.

It is an amenable number.

851021129 is a deficient number, since it is larger than the sum of its proper divisors (121574455).

851021129 is a wasteful number, since it uses less digits than its factorization.

851021129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121574454.

The product of its (nonzero) digits is 1440, while the sum is 29.

The square root of 851021129 is about 29172.2664357777. The cubic root of 851021129 is about 947.6474120818.

The spelling of 851021129 in words is "eight hundred fifty-one million, twenty-one thousand, one hundred twenty-nine".