851915421 has 24 divisors (see below), whose sum is σ = 1468155840. Its totient is φ = 486808056.

The previous prime is 851915411. The next prime is 851915453. The reversal of 851915421 is 124519158.

It is not a de Polignac number, because 851915421 - 2¹³ = 851907229 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851915411) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 320641 + ... + 323286.

It is an arithmetic number, because the mean of its divisors is an integer number (61173160).

Almost surely, 2^851915421 is an apocalyptic number.

It is an amenable number.

851915421 is a deficient number, since it is larger than the sum of its proper divisors (616240419).

851915421 is a wasteful number, since it uses less digits than its factorization.

851915421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643950 (or 643937 counting only the distinct ones).

The product of its digits is 14400, while the sum is 36.

The square root of 851915421 is about 29187.5901882975. The cubic root of 851915421 is about 947.9792396511.

The spelling of 851915421 in words is "eight hundred fifty-one million, nine hundred fifteen thousand, four hundred twenty-one".