16506423565 has 16 divisors (see below), whose sum is σ = 20908019520. Its totient is φ = 12510105552.

The previous prime is 16506423541. The next prime is 16506423589. The reversal of 16506423565 is 56532460561.

It is an interprime number because it is at equal distance from previous prime (16506423541) and next prime (16506423589).

It is not a de Polignac number, because 16506423565 - 2²¹ = 16504326413 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 206359 + ... + 274948.

It is an arithmetic number, because the mean of its divisors is an integer number (1306751220).

Almost surely, 2^16506423565 is an apocalyptic number.

It is an amenable number.

16506423565 is a deficient number, since it is larger than the sum of its proper divisors (4401595955).

16506423565 is an frugal number, since it uses more digits than its factorization.

16506423565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481369 (or 481331 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 43.

The spelling of 16506423565 in words is "sixteen billion, five hundred six million, four hundred twenty-three thousand, five hundred sixty-five".