1009857421 has 2 divisors, whose sum is σ = 1009857422. Its totient is φ = 1009857420.

The previous prime is 1009857419. The next prime is 1009857427. The reversal of 1009857421 is 1247589001.

1009857421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1000773225 + 9084196 = 31635^2 + 3014^2 .

It is a cyclic number.

It is not a de Polignac number, because 1009857421 - 2¹ = 1009857419 is a prime.

Together with 1009857419, 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 (1009857427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 504928710 + 504928711.

It is an arithmetic number, because the mean of its divisors is an integer number (504928711).

Almost surely, 2^1009857421 is an apocalyptic number.

It is an amenable number.

1009857421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1009857421 is an equidigital number, since it uses as much as digits as its factorization.

1009857421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 1009857421 is about 31778.2539010563. The cubic root of 1009857421 is about 1003.2750692121.

The spelling of 1009857421 in words is "one billion, nine million, eight hundred fifty-seven thousand, four hundred twenty-one".