42321731 has 2 divisors, whose sum is σ = 42321732. Its totient is φ = 42321730.

The previous prime is 42321659. The next prime is 42321749. The reversal of 42321731 is 13712324.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42321731 is a prime.

It is a super-2 number, since 2×42321731² = 3582257829672722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 42321697 and 42321706.

It is not a weakly prime, because it can be changed into another prime (42321781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21160865 + 21160866.

It is an arithmetic number, because the mean of its divisors is an integer number (21160866).

Almost surely, 2^42321731 is an apocalyptic number.

42321731 is a deficient number, since it is larger than the sum of its proper divisors (1).

42321731 is an equidigital number, since it uses as much as digits as its factorization.

42321731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 23.

The square root of 42321731 is about 6505.5154292339. The cubic root of 42321731 is about 348.4879835464.

The spelling of 42321731 in words is "forty-two million, three hundred twenty-one thousand, seven hundred thirty-one".