42669781 has 16 divisors (see below), whose sum is σ = 53706240. Its totient is φ = 32932080.

The previous prime is 42669721. The next prime is 42669797. The reversal of 42669781 is 18796624.

42669781 = 448² + 449² + ... + 601².

42669781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 42669781 - 2¹³ = 42661589 is a prime.

It is a super-2 number, since 2×42669781² = 3641420421175922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42669721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5650 + ... + 10828.

It is an arithmetic number, because the mean of its divisors is an integer number (3356640).

Almost surely, 2^42669781 is an apocalyptic number.

It is an amenable number.

42669781 is a deficient number, since it is larger than the sum of its proper divisors (11036459).

42669781 is a wasteful number, since it uses less digits than its factorization.

42669781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5304.

The product of its digits is 145152, while the sum is 43.

The square root of 42669781 is about 6532.2110345579. The cubic root of 42669781 is about 349.4406876275.

It can be divided in two parts, 426 and 69781, that added together give a palindrome (70207).

The spelling of 42669781 in words is "forty-two million, six hundred sixty-nine thousand, seven hundred eighty-one".