491627021 has 2 divisors, whose sum is σ = 491627022.
Its totient is φ = 491627020.
The previous prime is 491626997. The next prime is 491627069. The reversal of 491627021 is 120726194.
It is a happy number.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 315772900 + 175854121 = 17770^2 + 13261^2
It is a cyclic number.
It is not a de Polignac number, because 491627021 - 222 = 487432717 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is a Curzon number.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (491627221) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245813510 + 245813511.
It is an arithmetic number, because the mean of its divisors is an integer number (245813511).
Almost surely, 2491627021 is an apocalyptic number.
It is an amenable number.
491627021 is a deficient number, since it is larger than the sum of its proper divisors (1).
491627021 is an equidigital number, since it uses as much as digits as its factorization.
491627021 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 6048, while the sum is 32.
The square root of 491627021 is about 22172.6638228247.
The cubic root of 491627021 is about 789.2451375116.
The spelling of 491627021 in words is "four hundred ninety-one million, six hundred twenty-seven thousand, twenty-one".