2157642842 has 16 divisors (see below), whose sum is σ = 3378412800. Its totient is φ = 1032287520.

The previous prime is 2157642841. The next prime is 2157642847. The reversal of 2157642842 is 2482467512.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 2157642842.

It is not an unprimeable number, because it can be changed into a prime (2157642841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189992 + ... + 201027.

It is an arithmetic number, because the mean of its divisors is an integer number (211150800).

Almost surely, 2^2157642842 is an apocalyptic number.

2157642842 is a deficient number, since it is larger than the sum of its proper divisors (1220769958).

2157642842 is a wasteful number, since it uses less digits than its factorization.

2157642842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391141.

The product of its digits is 215040, while the sum is 41.

The square root of 2157642842 is about 46450.4342498539. The cubic root of 2157642842 is about 1292.1904259285.

The spelling of 2157642842 in words is "two billion, one hundred fifty-seven million, six hundred forty-two thousand, eight hundred forty-two".