16642643 has 6 divisors (see below), whose sum is σ = 17679516. Its totient is φ = 15663392.

The previous prime is 16642631. The next prime is 16642667. The reversal of 16642643 is 34624661.

It is not a de Polignac number, because 16642643 - 2¹⁸ = 16380499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16642243) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28505 + ... + 29082.

It is an arithmetic number, because the mean of its divisors is an integer number (2946586).

Almost surely, 2^16642643 is an apocalyptic number.

16642643 is a deficient number, since it is larger than the sum of its proper divisors (1036873).

16642643 is an equidigital number, since it uses as much as digits as its factorization.

16642643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57621 (or 57604 counting only the distinct ones).

The product of its digits is 20736, while the sum is 32.

The square root of 16642643 is about 4079.5395573520. The cubic root of 16642643 is about 255.3136880328.

The spelling of 16642643 in words is "sixteen million, six hundred forty-two thousand, six hundred forty-three".