18121610 has 16 divisors (see below), whose sum is σ = 35128296. Its totient is φ = 6691008.

The previous prime is 18121603. The next prime is 18121613. The reversal of 18121610 is 1612181.

It can be written as a sum of positive squares in 4 ways, for example, as 8567329 + 9554281 = 2927^2 + 3091^2 .

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

It is not an unprimeable number, because it can be changed into a prime (18121613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69569 + ... + 69828.

Almost surely, 2^18121610 is an apocalyptic number.

18121610 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18121610 is a deficient number, since it is larger than the sum of its proper divisors (17006686).

18121610 is a wasteful number, since it uses less digits than its factorization.

18121610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139417.

The product of its (nonzero) digits is 96, while the sum is 20.

The square root of 18121610 is about 4256.9484375548. The cubic root of 18121610 is about 262.6630159020.

Adding to 18121610 its reverse (1612181), we get a palindrome (19733791).

It can be divided in two parts, 1812 and 1610, that multiplied together give a triangular number (2917320 = T₂₄₁₅).

The spelling of 18121610 in words is "eighteen million, one hundred twenty-one thousand, six hundred ten".