1645553233 has 4 divisors (see below), whose sum is σ = 1742350500. Its totient is φ = 1548755968.

The previous prime is 1645553227. The next prime is 1645553243. The reversal of 1645553233 is 3323555461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3323555461 = 73 ⋅45528157.

It can be written as a sum of positive squares in 2 ways, for example, as 858021264 + 787531969 = 29292^2 + 28063^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645553233 - 2⁵ = 1645553201 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1645553192 and 1645553201.

It is not an unprimeable number, because it can be changed into a prime (1645553243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48398608 + ... + 48398641.

It is an arithmetic number, because the mean of its divisors is an integer number (435587625).

Almost surely, 2^1645553233 is an apocalyptic number.

It is an amenable number.

1645553233 is a deficient number, since it is larger than the sum of its proper divisors (96797267).

1645553233 is an equidigital number, since it uses as much as digits as its factorization.

1645553233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96797266.

The product of its digits is 162000, while the sum is 37.

The square root of 1645553233 is about 40565.4191769295. The cubic root of 1645553233 is about 1180.6032616316.

The spelling of 1645553233 in words is "one billion, six hundred forty-five million, five hundred fifty-three thousand, two hundred thirty-three".