16561490 has 16 divisors (see below), whose sum is σ = 32520960. Its totient is φ = 6022320.

The previous prime is 16561469. The next prime is 16561507. The reversal of 16561490 is 9416561.

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

It is a Curzon number.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75170 + ... + 75389.

It is an arithmetic number, because the mean of its divisors is an integer number (2032560).

Almost surely, 2^16561490 is an apocalyptic number.

16561490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16561490 is a deficient number, since it is larger than the sum of its proper divisors (15959470).

16561490 is a wasteful number, since it uses less digits than its factorization.

16561490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150577.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 16561490 is about 4069.5810595195. The cubic root of 16561490 is about 254.8980240715.

Subtracting from 16561490 its reverse (9416561), we obtain a square (7144929 = 2673²).

The spelling of 16561490 in words is "sixteen million, five hundred sixty-one thousand, four hundred ninety".