1646397775 has 12 divisors (see below), whose sum is σ = 2227127544. Its totient is φ = 1197380000.

The previous prime is 1646397757. The next prime is 1646397811. The reversal of 1646397775 is 5777936461.

It is not a de Polignac number, because 1646397775 - 2¹¹ = 1646395727 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2993176 + ... + 2993725.

It is an arithmetic number, because the mean of its divisors is an integer number (185593962).

Almost surely, 2^1646397775 is an apocalyptic number.

1646397775 is a deficient number, since it is larger than the sum of its proper divisors (580729769).

1646397775 is a wasteful number, since it uses less digits than its factorization.

1646397775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5986922 (or 5986917 counting only the distinct ones).

The product of its digits is 6667920, while the sum is 55.

The square root of 1646397775 is about 40575.8274715378. The cubic root of 1646397775 is about 1180.8051994954.

The spelling of 1646397775 in words is "one billion, six hundred forty-six million, three hundred ninety-seven thousand, seven hundred seventy-five".