18661451 has 4 divisors (see below), whose sum is σ = 18704400. Its totient is φ = 18618504.

The previous prime is 18661429. The next prime is 18661457. The reversal of 18661451 is 15416681.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18661451 - 2⁶ = 18661387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18661457) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20816 + ... + 21693.

It is an arithmetic number, because the mean of its divisors is an integer number (4676100).

Almost surely, 2^18661451 is an apocalyptic number.

18661451 is a deficient number, since it is larger than the sum of its proper divisors (42949).

18661451 is an equidigital number, since it uses as much as digits as its factorization.

18661451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42948.

The product of its digits is 5760, while the sum is 32.

The square root of 18661451 is about 4319.8901606407. The cubic root of 18661451 is about 265.2457717535.

The spelling of 18661451 in words is "eighteen million, six hundred sixty-one thousand, four hundred fifty-one".