42101666 has 4 divisors (see below), whose sum is σ = 63152502. Its totient is φ = 21050832.

The previous prime is 42101659. The next prime is 42101681. The reversal of 42101666 is 66610124.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 21353641 + 20748025 = 4621^2 + 4555^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10525415 + ... + 10525418.

Almost surely, 2^42101666 is an apocalyptic number.

42101666 is a deficient number, since it is larger than the sum of its proper divisors (21050836).

42101666 is a wasteful number, since it uses less digits than its factorization.

42101666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21050835.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 42101666 is about 6488.5796596790. The cubic root of 42101666 is about 347.8829096981.

The spelling of 42101666 in words is "forty-two million, one hundred one thousand, six hundred sixty-six".