18145557 has 24 divisors (see below), whose sum is σ = 27027000. Its totient is φ = 11726208.

The previous prime is 18145529. The next prime is 18145637. The reversal of 18145557 is 75554181.

It can be written as a sum of positive squares in 4 ways, for example, as 8071281 + 10074276 = 2841^2 + 3174^2 .

It is not a de Polignac number, because 18145557 - 2¹⁸ = 17883413 is a prime.

It is a super-2 number, since 2×18145557² = 658522477680498, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18145157) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51819 + ... + 52167.

It is an arithmetic number, because the mean of its divisors is an integer number (1126125).

Almost surely, 2^18145557 is an apocalyptic number.

It is an amenable number.

18145557 is a deficient number, since it is larger than the sum of its proper divisors (8881443).

18145557 is a wasteful number, since it uses less digits than its factorization.

18145557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 514 counting only the distinct ones).

The product of its digits is 28000, while the sum is 36.

The square root of 18145557 is about 4259.7602045186. The cubic root of 18145557 is about 262.7786646149.

The spelling of 18145557 in words is "eighteen million, one hundred forty-five thousand, five hundred fifty-seven".