842121890 has 16 divisors (see below), whose sum is σ = 1551071808. Its totient is φ = 329014896.

The previous prime is 842121871. The next prime is 842121967. The reversal of 842121890 is 98121248.

It is a self number, because there is not a number n which added to its sum of digits gives 842121890.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 978782 + ... + 979641.

It is an arithmetic number, because the mean of its divisors is an integer number (96941988).

Almost surely, 2^842121890 is an apocalyptic number.

842121890 is a deficient number, since it is larger than the sum of its proper divisors (708949918).

842121890 is a wasteful number, since it uses less digits than its factorization.

842121890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1958473.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 842121890 is about 29019.3364844891. The cubic root of 842121890 is about 944.3326064213.

The spelling of 842121890 in words is "eight hundred forty-two million, one hundred twenty-one thousand, eight hundred ninety".