641878723 has 2 divisors, whose sum is σ = 641878724. Its totient is φ = 641878722.

The previous prime is 641878711. The next prime is 641878747. The reversal of 641878723 is 327878146.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641878723 is a prime.

It is a super-2 number, since 2×641878723² = 824016590080221458, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (641878703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320939361 + 320939362.

It is an arithmetic number, because the mean of its divisors is an integer number (320939362).

Almost surely, 2^641878723 is an apocalyptic number.

641878723 is a deficient number, since it is larger than the sum of its proper divisors (1).

641878723 is an equidigital number, since it uses as much as digits as its factorization.

641878723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 451584, while the sum is 46.

The square root of 641878723 is about 25335.3255949080. The cubic root of 641878723 is about 862.6162993214.

The spelling of 641878723 in words is "six hundred forty-one million, eight hundred seventy-eight thousand, seven hundred twenty-three".