1618403787225 has 27 divisors (see below), whose sum is σ = 2898775184799. Its totient is φ = 863138509200.

The previous prime is 1618403787181. The next prime is 1618403787239. The reversal of 1618403787225 is 5227873048161.

The square root of 1618403787225 is 1272165.

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

1618403787225 is a `hidden beast` number, since 1 + 6 + 1 + 8 + 40 + 378 + 7 + 225 = 666.

It can be written as a sum of positive squares in only one way, i.e., 582625363401 + 1035778423824 = 763299^2 + 1017732^2 .

It is not a de Polignac number, because 1618403787225 - 2²⁵ = 1618370232793 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 19040070 + ... + 19124880.

Almost surely, 2^{1618403787225} is an apocalyptic number.

1618403787225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1618403787225 is the 1272165-th square number.

1618403787225 is the 636083-rd centered octagonal number.

It is an amenable number.

1618403787225 is a deficient number, since it is larger than the sum of its proper divisors (1280371397574).

1618403787225 is an frugal number, since it uses more digits than its factorization.

1618403787225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169638 (or 84819 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 54.

The spelling of 1618403787225 in words is "one trillion, six hundred eighteen billion, four hundred three million, seven hundred eighty-seven thousand, two hundred twenty-five".