193917421 has 2 divisors, whose sum is σ = 193917422. Its totient is φ = 193917420.

The previous prime is 193917397. The next prime is 193917463. The reversal of 193917421 is 124719391.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179854921 + 14062500 = 13411^2 + 3750^2 .

It is an emirp because it is prime and its reverse (124719391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 193917421 - 2¹³ = 193909229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (193917221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96958710 + 96958711.

It is an arithmetic number, because the mean of its divisors is an integer number (96958711).

Almost surely, 2^193917421 is an apocalyptic number.

It is an amenable number.

193917421 is a deficient number, since it is larger than the sum of its proper divisors (1).

193917421 is an equidigital number, since it uses as much as digits as its factorization.

193917421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 37.

The square root of 193917421 is about 13925.4235483162. The cubic root of 193917421 is about 578.8138869650.

The spelling of 193917421 in words is "one hundred ninety-three million, nine hundred seventeen thousand, four hundred twenty-one".