18661236450442 has 4 divisors (see below), whose sum is σ = 27991854675666. Its totient is φ = 9330618225220.

The previous prime is 18661236450391. The next prime is 18661236450533. The reversal of 18661236450442 is 24405463216681.

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

It can be written as a sum of positive squares in only one way, i.e., 11179266418681 + 7481970031761 = 3343541^2 + 2735319^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18661236450442.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4665309112609 + ... + 4665309112612.

Almost surely, 2^{18661236450442} is an apocalyptic number.

18661236450442 is a deficient number, since it is larger than the sum of its proper divisors (9330618225224).

18661236450442 is an equidigital number, since it uses as much as digits as its factorization.

18661236450442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9330618225223.

The product of its (nonzero) digits is 6635520, while the sum is 52.

The spelling of 18661236450442 in words is "eighteen trillion, six hundred sixty-one billion, two hundred thirty-six million, four hundred fifty thousand, four hundred forty-two".