73431431 has 2 divisors, whose sum is σ = 73431432. Its totient is φ = 73431430.

The previous prime is 73431419. The next prime is 73431439. The reversal of 73431431 is 13413437.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73431431 is a prime.

It is a super-2 number, since 2×73431431² = 10784350117415522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 73431431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73431439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36715715 + 36715716.

It is an arithmetic number, because the mean of its divisors is an integer number (36715716).

Almost surely, 2^73431431 is an apocalyptic number.

73431431 is a deficient number, since it is larger than the sum of its proper divisors (1).

73431431 is an equidigital number, since it uses as much as digits as its factorization.

73431431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 26.

The square root of 73431431 is about 8569.2141413317. The cubic root of 73431431 is about 418.7556347055.

Adding to 73431431 its reverse (13413437), we get a palindrome (86844868).

The spelling of 73431431 in words is "seventy-three million, four hundred thirty-one thousand, four hundred thirty-one".