16620161506605 has 24 divisors (see below), whose sum is σ = 28830087981240. Its totient is φ = 8857375971840.

The previous prime is 16620161506549. The next prime is 16620161506643. The reversal of 16620161506605 is 50660516102661.

16620161506605 is a `hidden beast` number, since 1 + 6 + 6 + 20 + 1 + 6 + 15 + 0 + 6 + 605 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4194050051844 + 12426111454761 = 2047938^2 + 3525069^2 .

It is not a de Polignac number, because 16620161506605 - 2³⁴ = 16602981637421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 139735000 + ... + 139853889.

It is an arithmetic number, because the mean of its divisors is an integer number (1201253665885).

Almost surely, 2^{16620161506605} is an apocalyptic number.

16620161506605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16620161506605 is a deficient number, since it is larger than the sum of its proper divisors (12209926474635).

16620161506605 is a wasteful number, since it uses less digits than its factorization.

16620161506605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279590221 (or 279590218 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 16620161506605 in words is "sixteen trillion, six hundred twenty billion, one hundred sixty-one million, five hundred six thousand, six hundred five".