1645155254 has 4 divisors (see below), whose sum is σ = 2467732884. Its totient is φ = 822577626.

The previous prime is 1645155227. The next prime is 1645155257. The reversal of 1645155254 is 4525515461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4525515461 = 47 ⋅96287563.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645155257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411288812 + ... + 411288815.

It is an arithmetic number, because the mean of its divisors is an integer number (616933221).

Almost surely, 2^1645155254 is an apocalyptic number.

1645155254 is a deficient number, since it is larger than the sum of its proper divisors (822577630).

1645155254 is an equidigital number, since it uses as much as digits as its factorization.

1645155254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822577629.

The product of its digits is 120000, while the sum is 38.

The square root of 1645155254 is about 40560.5134829430. The cubic root of 1645155254 is about 1180.5080771916.

The spelling of 1645155254 in words is "one billion, six hundred forty-five million, one hundred fifty-five thousand, two hundred fifty-four".