42121779 has 8 divisors (see below), whose sum is σ = 64185600. Its totient is φ = 24069576.

The previous prime is 42121741. The next prime is 42121787. The reversal of 42121779 is 97712124.

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

It is not a de Polignac number, because 42121779 - 2²⁰ = 41073203 is a prime.

It is a super-2 number, since 2×42121779² = 3548488532249682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (42121279) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1002879 + ... + 1002920.

It is an arithmetic number, because the mean of its divisors is an integer number (8023200).

Almost surely, 2^42121779 is an apocalyptic number.

42121779 is a deficient number, since it is larger than the sum of its proper divisors (22063821).

42121779 is a wasteful number, since it uses less digits than its factorization.

42121779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2005809.

The product of its digits is 7056, while the sum is 33.

The square root of 42121779 is about 6490.1293515615. The cubic root of 42121779 is about 347.9382982825.

The spelling of 42121779 in words is "forty-two million, one hundred twenty-one thousand, seven hundred seventy-nine".