1642221798 has 16 divisors (see below), whose sum is σ = 3753649920. Its totient is φ = 469206216.

The previous prime is 1642221767. The next prime is 1642221817. The reversal of 1642221798 is 8971222461.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 39100519 = 1642221798 / (1 + 6 + 4 + 2 + 2 + 2 + 1 + 7 + 9 + 8).

It is a Curzon number.

It is a congruent number.

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, 19550218 + ... + 19550301.

It is an arithmetic number, because the mean of its divisors is an integer number (234603120).

Almost surely, 2^1642221798 is an apocalyptic number.

1642221798 is an abundant number, since it is smaller than the sum of its proper divisors (2111428122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1642221798 is a wasteful number, since it uses less digits than its factorization.

1642221798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39100531.

The product of its digits is 96768, while the sum is 42.

The square root of 1642221798 is about 40524.3358736451. The cubic root of 1642221798 is about 1179.8060099563.

The spelling of 1642221798 in words is "one billion, six hundred forty-two million, two hundred twenty-one thousand, seven hundred ninety-eight".