42121918 has 4 divisors (see below), whose sum is σ = 63182880. Its totient is φ = 21060958.

The previous prime is 42121913. The next prime is 42121927. The reversal of 42121918 is 81912124.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42121913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10530478 + ... + 10530481.

It is an arithmetic number, because the mean of its divisors is an integer number (15795720).

Almost surely, 2^42121918 is an apocalyptic number.

42121918 is a deficient number, since it is larger than the sum of its proper divisors (21060962).

42121918 is a wasteful number, since it uses less digits than its factorization.

42121918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21060961.

The product of its digits is 1152, while the sum is 28.

The square root of 42121918 is about 6490.1400601220. The cubic root of 42121918 is about 347.9386810091.

The spelling of 42121918 in words is "forty-two million, one hundred twenty-one thousand, nine hundred eighteen".