42251531 has 4 divisors (see below), whose sum is σ = 48287472. Its totient is φ = 36215592.

The previous prime is 42251513. The next prime is 42251549. The reversal of 42251531 is 13515224.

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

It is an interprime number because it is at equal distance from previous prime (42251513) and next prime (42251549).

It is a de Polignac number, because none of the positive numbers 2^k-42251531 is a prime.

It is a super-2 number, since 2×42251531² = 3570383743687922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42251497 and 42251506.

It is not an unprimeable number, because it can be changed into a prime (42251591) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 3017960 + ... + 3017973.

It is an arithmetic number, because the mean of its divisors is an integer number (12071868).

Almost surely, 2^42251531 is an apocalyptic number.

42251531 is a deficient number, since it is larger than the sum of its proper divisors (6035941).

42251531 is an equidigital number, since it uses as much as digits as its factorization.

42251531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6035940.

The product of its digits is 1200, while the sum is 23.

The square root of 42251531 is about 6500.1177681639. The cubic root of 42251531 is about 348.2951953138.

Adding to 42251531 its reverse (13515224), we get a palindrome (55766755).

The spelling of 42251531 in words is "forty-two million, two hundred fifty-one thousand, five hundred thirty-one".