921540493 has 2 divisors, whose sum is σ = 921540494. Its totient is φ = 921540492.

The previous prime is 921540491. The next prime is 921540523. The reversal of 921540493 is 394045129.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 890604649 + 30935844 = 29843^2 + 5562^2 .

It is a cyclic number.

It is not a de Polignac number, because 921540493 - 2¹ = 921540491 is a prime.

Together with 921540491, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (921540491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460770246 + 460770247.

It is an arithmetic number, because the mean of its divisors is an integer number (460770247).

Almost surely, 2^921540493 is an apocalyptic number.

It is an amenable number.

921540493 is a deficient number, since it is larger than the sum of its proper divisors (1).

921540493 is an equidigital number, since it uses as much as digits as its factorization.

921540493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 921540493 is about 30356.8854298329. The cubic root of 921540493 is about 973.1313736098.

The spelling of 921540493 in words is "nine hundred twenty-one million, five hundred forty thousand, four hundred ninety-three".