42072431 has 2 divisors, whose sum is σ = 42072432. Its totient is φ = 42072430.

The previous prime is 42072421. The next prime is 42072439. The reversal of 42072431 is 13427024.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42072431 is a prime.

It is a super-2 number, since 2×42072431² = 3540178900499522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42072397 and 42072406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42072439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21036215 + 21036216.

It is an arithmetic number, because the mean of its divisors is an integer number (21036216).

Almost surely, 2^42072431 is an apocalyptic number.

42072431 is a deficient number, since it is larger than the sum of its proper divisors (1).

42072431 is an equidigital number, since it uses as much as digits as its factorization.

42072431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 42072431 is about 6486.3264641860. The cubic root of 42072431 is about 347.8023688485.

Adding to 42072431 its reverse (13427024), we get a palindrome (55499455).

The spelling of 42072431 in words is "forty-two million, seventy-two thousand, four hundred thirty-one".