42666551 has 4 divisors (see below), whose sum is σ = 42691272. Its totient is φ = 42641832.

The previous prime is 42666523. The next prime is 42666577. The reversal of 42666551 is 15566624.

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

It is a cyclic number.

It is not a de Polignac number, because 42666551 - 2¹⁰ = 42665527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42666581) 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, 9560 + ... + 13293.

It is an arithmetic number, because the mean of its divisors is an integer number (10672818).

Almost surely, 2^42666551 is an apocalyptic number.

42666551 is a deficient number, since it is larger than the sum of its proper divisors (24721).

42666551 is a wasteful number, since it uses less digits than its factorization.

42666551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24720.

The product of its digits is 43200, while the sum is 35.

The square root of 42666551 is about 6531.9637935310. The cubic root of 42666551 is about 349.4318701313.

The spelling of 42666551 in words is "forty-two million, six hundred sixty-six thousand, five hundred fifty-one".