646738153 has 4 divisors (see below), whose sum is σ = 646832340. Its totient is φ = 646643968.

The previous prime is 646738129. The next prime is 646738177. The reversal of 646738153 is 351837646.

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

It is an interprime number because it is at equal distance from previous prime (646738129) and next prime (646738177).

It can be written as a sum of positive squares in 2 ways, for example, as 287370304 + 359367849 = 16952^2 + 18957^2 .

It is a cyclic number.

It is not a de Polignac number, because 646738153 - 2⁵ = 646738121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646738453) 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, 35908 + ... + 50821.

It is an arithmetic number, because the mean of its divisors is an integer number (161708085).

Almost surely, 2^646738153 is an apocalyptic number.

It is an amenable number.

646738153 is a deficient number, since it is larger than the sum of its proper divisors (94187).

646738153 is an equidigital number, since it uses as much as digits as its factorization.

646738153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94186.

The product of its digits is 362880, while the sum is 43.

The square root of 646738153 is about 25431.0470291728. The cubic root of 646738153 is about 864.7876801888.

The spelling of 646738153 in words is "six hundred forty-six million, seven hundred thirty-eight thousand, one hundred fifty-three".