42345621 has 12 divisors (see below), whose sum is σ = 62004748. Its totient is φ = 27843264.

The previous prime is 42345617. The next prime is 42345631. The reversal of 42345621 is 12654324.

42345621 is a `hidden beast` number, since 4 + 2 + 34 + 5 + 621 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7700625 + 34644996 = 2775^2 + 5886^2 .

It is not a de Polignac number, because 42345621 - 2² = 42345617 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 (42345631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31570 + ... + 32883.

Almost surely, 2^42345621 is an apocalyptic number.

It is an amenable number.

42345621 is a deficient number, since it is larger than the sum of its proper divisors (19659127).

42345621 is a wasteful number, since it uses less digits than its factorization.

42345621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64532 (or 64529 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 42345621 is about 6507.3513044863. The cubic root of 42345621 is about 348.5535433405.

Adding to 42345621 its reverse (12654324), we get a palindrome (54999945).

The spelling of 42345621 in words is "forty-two million, three hundred forty-five thousand, six hundred twenty-one".