646498019 has 4 divisors (see below), whose sum is σ = 660253344. Its totient is φ = 632742696.

The previous prime is 646497997. The next prime is 646498033. The reversal of 646498019 is 910894646.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646498019 - 2¹⁶ = 646432483 is a prime.

It is a super-2 number, since 2×646498019² = 835919377141848722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 13755277 = 646498019 / (6 + 4 + 6 + 4 + 9 + 8 + 0 + 1 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646498319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6877592 + ... + 6877685.

It is an arithmetic number, because the mean of its divisors is an integer number (165063336).

Almost surely, 2^646498019 is an apocalyptic number.

646498019 is a deficient number, since it is larger than the sum of its proper divisors (13755325).

646498019 is a wasteful number, since it uses less digits than its factorization.

646498019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13755324.

The product of its (nonzero) digits is 373248, while the sum is 47.

The square root of 646498019 is about 25426.3253145239. The cubic root of 646498019 is about 864.6806349953.

The spelling of 646498019 in words is "six hundred forty-six million, four hundred ninety-eight thousand, nineteen".