1665412553 has 8 divisors (see below), whose sum is σ = 1906145472. Its totient is φ = 1425383856.

The previous prime is 1665412517. The next prime is 1665412559. The reversal of 1665412553 is 3552145661.

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

It is a cyclic number.

It is not a de Polignac number, because 1665412553 - 2²⁴ = 1648635337 is a prime.

It is a super-3 number, since 3×1665412553³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1665412559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170975 + ... + 180452.

It is an arithmetic number, because the mean of its divisors is an integer number (238268184).

Almost surely, 2^1665412553 is an apocalyptic number.

It is an amenable number.

1665412553 is a deficient number, since it is larger than the sum of its proper divisors (240732919).

1665412553 is an equidigital number, since it uses as much as digits as its factorization.

1665412553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352111.

The product of its digits is 108000, while the sum is 38.

The square root of 1665412553 is about 40809.4664630647. The cubic root of 1665412553 is about 1185.3336436414. Note that the first 3 decimals are identical.

The spelling of 1665412553 in words is "one billion, six hundred sixty-five million, four hundred twelve thousand, five hundred fifty-three".