16561270 has 24 divisors (see below), whose sum is σ = 32769072. Its totient is φ = 6021840.

The previous prime is 16561243. The next prime is 16561271. The reversal of 16561270 is 7216561.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5634 + ... + 8053.

It is an arithmetic number, because the mean of its divisors is an integer number (1365378).

Almost surely, 2^16561270 is an apocalyptic number.

16561270 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16561270 is a deficient number, since it is larger than the sum of its proper divisors (16207802).

16561270 is a wasteful number, since it uses less digits than its factorization.

16561270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13716 (or 13705 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 16561270 is about 4069.5540296204. The cubic root of 16561270 is about 254.8968953926.

It can be divided in two parts, 1656 and 1270, that added together give a triangular number (2926 = T₇₆).

The spelling of 16561270 in words is "sixteen million, five hundred sixty-one thousand, two hundred seventy".