1645494187 has 2 divisors, whose sum is σ = 1645494188. Its totient is φ = 1645494186.

The previous prime is 1645494143. The next prime is 1645494197. The reversal of 1645494187 is 7814945461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1645494187 - 2¹⁹ = 1644969899 is a prime.

It is a super-2 number, since 2×1645494187² = 5415302238901581938, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1645494187.

It is not a weakly prime, because it can be changed into another prime (1645494197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822747093 + 822747094.

It is an arithmetic number, because the mean of its divisors is an integer number (822747094).

Almost surely, 2^1645494187 is an apocalyptic number.

1645494187 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645494187 is an equidigital number, since it uses as much as digits as its factorization.

1645494187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 967680, while the sum is 49.

The square root of 1645494187 is about 40564.6913830242. The cubic root of 1645494187 is about 1180.5891405987.

The spelling of 1645494187 in words is "one billion, six hundred forty-five million, four hundred ninety-four thousand, one hundred eighty-seven".