1218220715 has 8 divisors (see below), whose sum is σ = 1481890848. Its totient is φ = 961225920.

The previous prime is 1218220709. The next prime is 1218220723. The reversal of 1218220715 is 5170228121.

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

It is not a de Polignac number, because 1218220715 - 2⁴ = 1218220699 is a prime.

It is a super-2 number, since 2×1218220715² = 2968123420910222450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1668431 + ... + 1669160.

It is an arithmetic number, because the mean of its divisors is an integer number (185236356).

Almost surely, 2^1218220715 is an apocalyptic number.

1218220715 is a deficient number, since it is larger than the sum of its proper divisors (263670133).

1218220715 is an equidigital number, since it uses as much as digits as its factorization.

1218220715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3337669.

The product of its (nonzero) digits is 2240, while the sum is 29.

The square root of 1218220715 is about 34903.0187089885. The cubic root of 1218220715 is about 1068.0100186911.

Adding to 1218220715 its reverse (5170228121), we get a palindrome (6388448836).

The spelling of 1218220715 in words is "one billion, two hundred eighteen million, two hundred twenty thousand, seven hundred fifteen".