18219061 has 4 divisors (see below), whose sum is σ = 20821792. Its totient is φ = 15616332.

The previous prime is 18219037. The next prime is 18219077. The reversal of 18219061 is 16091281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16091281 = 127 ⋅126703.

It is a cyclic number.

It is not a de Polignac number, because 18219061 - 2²¹ = 16121909 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 (18219001) 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, 1301355 + ... + 1301368.

It is an arithmetic number, because the mean of its divisors is an integer number (5205448).

Almost surely, 2^18219061 is an apocalyptic number.

It is an amenable number.

18219061 is a deficient number, since it is larger than the sum of its proper divisors (2602731).

18219061 is an equidigital number, since it uses as much as digits as its factorization.

18219061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2602730.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 18219061 is about 4268.3792005866. The cubic root of 18219061 is about 263.1330077511.

The spelling of 18219061 in words is "eighteen million, two hundred nineteen thousand, sixty-one".