1645291 has 2 divisors, whose sum is σ = 1645292. Its totient is φ = 1645290.

The previous prime is 1645253. The next prime is 1645327. The reversal of 1645291 is 1925461.

It is a strong prime.

It is an emirp because it is prime and its reverse (1925461) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1645291 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (1645211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822645 + 822646.

It is an arithmetic number, because the mean of its divisors is an integer number (822646).

2^1645291 is an apocalyptic number.

1645291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645291 is an equidigital number, since it uses as much as digits as its factorization.

1645291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 28.

The square root of 1645291 is about 1282.6889724325. The cubic root of 1645291 is about 118.0540545220.

It can be divided in two parts, 1645 and 291, that added together give a square (1936 = 44²).

The spelling of 1645291 in words is "one million, six hundred forty-five thousand, two hundred ninety-one".