1618430221 has 8 divisors (see below), whose sum is σ = 1644846840. Its totient is φ = 1592128512.

The previous prime is 1618430189. The next prime is 1618430263. The reversal of 1618430221 is 1220348161.

It can be written as a sum of positive squares in 4 ways, for example, as 319908996 + 1298521225 = 17886^2 + 36035^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1618430221 - 2⁵ = 1618430189 is a prime.

It is a super-2 number, since 2×1618430221² = 5238632760492217682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1618430221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1618430291) 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, 100 + ... + 56893.

It is an arithmetic number, because the mean of its divisors is an integer number (205605855).

Almost surely, 2^1618430221 is an apocalyptic number.

It is an amenable number.

1618430221 is a deficient number, since it is larger than the sum of its proper divisors (26416619).

1618430221 is an equidigital number, since it uses as much as digits as its factorization.

1618430221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57455.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 1618430221 is about 40229.7181322465. The cubic root of 1618430221 is about 1174.0808193218.

Adding to 1618430221 its reverse (1220348161), we get a palindrome (2838778382).

The spelling of 1618430221 in words is "one billion, six hundred eighteen million, four hundred thirty thousand, two hundred twenty-one".