1618641925 has 6 divisors (see below), whose sum is σ = 2007116018. Its totient is φ = 1294913520.

The previous prime is 1618641907. The next prime is 1618641929. The reversal of 1618641925 is 5291468161.

It can be written as a sum of positive squares in 3 ways, for example, as 23677956 + 1594963969 = 4866^2 + 39937^2 .

It is not a de Polignac number, because 1618641925 - 2¹⁷ = 1618510853 is a prime.

It is a super-5 number, since 5×1618641925⁵ (a number of 47 digits) contains 55555 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1618641929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 32372814 + ... + 32372863.

Almost surely, 2^1618641925 is an apocalyptic number.

It is an amenable number.

1618641925 is a deficient number, since it is larger than the sum of its proper divisors (388474093).

1618641925 is an equidigital number, since it uses as much as digits as its factorization.

1618641925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64745687 (or 64745682 counting only the distinct ones).

The product of its digits is 103680, while the sum is 43.

The square root of 1618641925 is about 40232.3492354101. The cubic root of 1618641925 is about 1174.1320102362.

The spelling of 1618641925 in words is "one billion, six hundred eighteen million, six hundred forty-one thousand, nine hundred twenty-five".