646619091 has 16 divisors (see below), whose sum is σ = 881362944. Its totient is φ = 421495424.

The previous prime is 646619011. The next prime is 646619107. The reversal of 646619091 is 190916646.

It is a cyclic number.

It is not a de Polignac number, because 646619091 - 2¹¹ = 646617043 is a prime.

It is not an unprimeable number, because it can be changed into a prime (646619011) 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 15 ways as a sum of consecutive naturals, for example, 221755 + ... + 224651.

It is an arithmetic number, because the mean of its divisors is an integer number (55085184).

Almost surely, 2^646619091 is an apocalyptic number.

646619091 is a deficient number, since it is larger than the sum of its proper divisors (234743853).

646619091 is a wasteful number, since it uses less digits than its factorization.

646619091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4530.

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 646619091 is about 25428.7060425811. The cubic root of 646619091 is about 864.7346089062.

The spelling of 646619091 in words is "six hundred forty-six million, six hundred nineteen thousand, ninety-one".