42198731 has 2 divisors, whose sum is σ = 42198732. Its totient is φ = 42198730.

The previous prime is 42198707. The next prime is 42198733. The reversal of 42198731 is 13789124.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42198731 is a prime.

It is a super-2 number, since 2×42198731² = 3561465796020722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 42198733, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 42198691 and 42198700.

It is not a weakly prime, because it can be changed into another prime (42198733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21099365 + 21099366.

It is an arithmetic number, because the mean of its divisors is an integer number (21099366).

Almost surely, 2^42198731 is an apocalyptic number.

42198731 is a deficient number, since it is larger than the sum of its proper divisors (1).

42198731 is an equidigital number, since it uses as much as digits as its factorization.

42198731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 42198731 is about 6496.0550336339. The cubic root of 42198731 is about 348.1500514448.

The spelling of 42198731 in words is "forty-two million, one hundred ninety-eight thousand, seven hundred thirty-one".