18988061 has 4 divisors (see below), whose sum is σ = 19201500. Its totient is φ = 18774624.

The previous prime is 18988037. The next prime is 18988091. The reversal of 18988061 is 16088981.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1188100 + 17799961 = 1090^2 + 4219^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18988061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18988091) 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, 106586 + ... + 106763.

It is an arithmetic number, because the mean of its divisors is an integer number (4800375).

Almost surely, 2^18988061 is an apocalyptic number.

It is an amenable number.

18988061 is a deficient number, since it is larger than the sum of its proper divisors (213439).

18988061 is an equidigital number, since it uses as much as digits as its factorization.

18988061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213438.

The product of its (nonzero) digits is 27648, while the sum is 41.

The square root of 18988061 is about 4357.5292311125. The cubic root of 18988061 is about 266.7842618503.

The spelling of 18988061 in words is "eighteen million, nine hundred eighty-eight thousand, sixty-one".