1618855225 has 27 divisors (see below), whose sum is σ = 2177189613. Its totient is φ = 1193531040.

The previous prime is 1618855219. The next prime is 1618855229. The reversal of 1618855225 is 5225588161.

The square root of 1618855225 is 40235.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 417262329 + 1201592896 = 20427^2 + 34664^2 .

It is not a de Polignac number, because 1618855225 - 2⁷ = 1618855097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1618855229) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2614966 + ... + 2615584.

Almost surely, 2^1618855225 is an apocalyptic number.

1618855225 is the 40235-th square number.

1618855225 is the 20118-th centered octagonal number.

It is an amenable number.

1618855225 is a deficient number, since it is larger than the sum of its proper divisors (558334388).

1618855225 is an frugal number, since it uses more digits than its factorization.

1618855225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274 (or 637 counting only the distinct ones).

The product of its digits is 192000, while the sum is 43.

The cubic root of 1618855225 is about 1174.1835825561.

The spelling of 1618855225 in words is "one billion, six hundred eighteen million, eight hundred fifty-five thousand, two hundred twenty-five".