1864197397 has 4 divisors (see below), whose sum is σ = 1864750860. Its totient is φ = 1863643936.

The previous prime is 1864197383. The next prime is 1864197421. The reversal of 1864197397 is 7937914681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7937914681 = 43 ⋅184602667.

It can be written as a sum of positive squares in 2 ways, for example, as 1483713361 + 380484036 = 38519^2 + 19506^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1864197397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1864197337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271648 + ... + 278425.

It is an arithmetic number, because the mean of its divisors is an integer number (466187715).

Almost surely, 2^1864197397 is an apocalyptic number.

It is an amenable number.

1864197397 is a deficient number, since it is larger than the sum of its proper divisors (553463).

1864197397 is an equidigital number, since it uses as much as digits as its factorization.

1864197397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553462.

The product of its digits is 2286144, while the sum is 55.

The square root of 1864197397 is about 43176.3522891872. The cubic root of 1864197397 is about 1230.7333404207.

The spelling of 1864197397 in words is "one billion, eight hundred sixty-four million, one hundred ninety-seven thousand, three hundred ninety-seven".