42215731 has 2 divisors, whose sum is σ = 42215732. Its totient is φ = 42215730.

The previous prime is 42215713. The next prime is 42215749. The reversal of 42215731 is 13751224.

It is a happy number.

Together with previous prime (42215713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (42215713) and next prime (42215749).

It is a cyclic number.

It is not a de Polignac number, because 42215731 - 2⁵ = 42215699 is a prime.

It is a super-2 number, since 2×42215731² = 3564335887728722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42215696 and 42215705.

It is not a weakly prime, because it can be changed into another prime (42215791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21107865 + 21107866.

It is an arithmetic number, because the mean of its divisors is an integer number (21107866).

Almost surely, 2^42215731 is an apocalyptic number.

42215731 is a deficient number, since it is larger than the sum of its proper divisors (1).

42215731 is an equidigital number, since it uses as much as digits as its factorization.

42215731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 25.

The square root of 42215731 is about 6497.3633883291. The cubic root of 42215731 is about 348.1967965809.

Adding to 42215731 its reverse (13751224), we get a palindrome (55966955).

The spelling of 42215731 in words is "forty-two million, two hundred fifteen thousand, seven hundred thirty-one".