16640731 has 2 divisors, whose sum is σ = 16640732. Its totient is φ = 16640730.

The previous prime is 16640681. The next prime is 16640759. The reversal of 16640731 is 13704661.

It is an a-pointer prime, because the next prime (16640759) can be obtained adding 16640731 to its sum of digits (28).

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16640731 is a prime.

It is a super-2 number, since 2×16640731² = 553827856428722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16640731.

It is not a weakly prime, because it can be changed into another prime (16640761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8320365 + 8320366.

It is an arithmetic number, because the mean of its divisors is an integer number (8320366).

Almost surely, 2^16640731 is an apocalyptic number.

16640731 is a deficient number, since it is larger than the sum of its proper divisors (1).

16640731 is an equidigital number, since it uses as much as digits as its factorization.

16640731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 16640731 is about 4079.3052104494. The cubic root of 16640731 is about 255.3039103697.

It can be divided in two parts, 16640 and 731, that added together give a palindrome (17371).

The spelling of 16640731 in words is "sixteen million, six hundred forty thousand, seven hundred thirty-one".