1645494197 has 2 divisors, whose sum is σ = 1645494198. Its totient is φ = 1645494196.

The previous prime is 1645494187. The next prime is 1645494199. The reversal of 1645494197 is 7914945461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1638144676 + 7349521 = 40474^2 + 2711^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645494197 - 2¹⁶ = 1645428661 is a prime.

Together with 1645494199, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1645494199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822747098 + 822747099.

It is an arithmetic number, because the mean of its divisors is an integer number (822747099).

Almost surely, 2^1645494197 is an apocalyptic number.

It is an amenable number.

1645494197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645494197 is an equidigital number, since it uses as much as digits as its factorization.

1645494197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1088640, while the sum is 50.

The square root of 1645494197 is about 40564.6915062841. The cubic root of 1645494197 is about 1180.5891429902.

The spelling of 1645494197 in words is "one billion, six hundred forty-five million, four hundred ninety-four thousand, one hundred ninety-seven".