1930857421 has 2 divisors, whose sum is σ = 1930857422. Its totient is φ = 1930857420.

The previous prime is 1930857419. The next prime is 1930857443. The reversal of 1930857421 is 1247580391.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1928439396 + 2418025 = 43914^2 + 1555^2 .

It is an emirp because it is prime and its reverse (1247580391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1930857421 - 2¹ = 1930857419 is a prime.

Together with 1930857419, 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 (1930857451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 965428710 + 965428711.

It is an arithmetic number, because the mean of its divisors is an integer number (965428711).

Almost surely, 2^1930857421 is an apocalyptic number.

It is an amenable number.

1930857421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1930857421 is an equidigital number, since it uses as much as digits as its factorization.

1930857421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 1930857421 is about 43941.5227433006. The cubic root of 1930857421 is about 1245.2314147552.

It can be divided in two parts, 19308 and 57421, that added together give a square (76729 = 277²).

The spelling of 1930857421 in words is "one billion, nine hundred thirty million, eight hundred fifty-seven thousand, four hundred twenty-one".