2157840042 has 8 divisors (see below), whose sum is σ = 4315680096. Its totient is φ = 719280012.

The previous prime is 2157840011. The next prime is 2157840043. The reversal of 2157840042 is 2400487512.

It is a sphenic number, since it is the product of 3 distinct primes.

2157840042 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 2157839985 and 2157840012.

It is not an unprimeable number, because it can be changed into a prime (2157840043) 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, 179819998 + ... + 179820009.

It is an arithmetic number, because the mean of its divisors is an integer number (539460012).

Almost surely, 2^2157840042 is an apocalyptic number.

2157840042 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2157840042 is a wasteful number, since it uses less digits than its factorization.

2157840042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359640012.

The product of its (nonzero) digits is 17920, while the sum is 33.

The square root of 2157840042 is about 46452.5568941043. The cubic root of 2157840042 is about 1292.2297917562.

The spelling of 2157840042 in words is "two billion, one hundred fifty-seven million, eight hundred forty thousand, forty-two".