42409251 has 10 divisors (see below), whose sum is σ = 63352212. Its totient is φ = 28272780.

The previous prime is 42409249. The next prime is 42409253. The reversal of 42409251 is 15290424.

42409251 is a `hidden beast` number, since 4 + 2 + 409 + 251 = 666.

It is an interprime number because it is at equal distance from previous prime (42409249) and next prime (42409253).

It is not a de Polignac number, because 42409251 - 2¹ = 42409249 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (42409253) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 261705 + ... + 261866.

Almost surely, 2^42409251 is an apocalyptic number.

42409251 is a deficient number, since it is larger than the sum of its proper divisors (20942961).

42409251 is an equidigital number, since it uses as much as digits as its factorization.

42409251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523583 (or 523574 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 42409251 is about 6512.2385552128. The cubic root of 42409251 is about 348.7280388530.

Adding to 42409251 its reverse (15290424), we get a palindrome (57699675).

The spelling of 42409251 in words is "forty-two million, four hundred nine thousand, two hundred fifty-one".