421916381 has 2 divisors, whose sum is σ = 421916382. Its totient is φ = 421916380.

The previous prime is 421916359. The next prime is 421916423. The reversal of 421916381 is 183619124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 397364356 + 24552025 = 19934^2 + 4955^2 .

It is a cyclic number.

It is not a de Polignac number, because 421916381 - 2¹⁸ = 421654237 is a prime.

It is a super-2 number, since 2×421916381² = 356026865112274322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421916351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210958190 + 210958191.

It is an arithmetic number, because the mean of its divisors is an integer number (210958191).

Almost surely, 2^421916381 is an apocalyptic number.

It is an amenable number.

421916381 is a deficient number, since it is larger than the sum of its proper divisors (1).

421916381 is an equidigital number, since it uses as much as digits as its factorization.

421916381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The square root of 421916381 is about 20540.6032287272. The cubic root of 421916381 is about 750.0245212723.

The spelling of 421916381 in words is "four hundred twenty-one million, nine hundred sixteen thousand, three hundred eighty-one".