394332511421 has 2 divisors, whose sum is σ = 394332511422. Its totient is φ = 394332511420.

The previous prime is 394332511409. The next prime is 394332511481. The reversal of 394332511421 is 124115233493.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 322930792900 + 71401718521 = 568270^2 + 267211^2 .

It is an emirp because it is prime and its reverse (124115233493) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-394332511421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394332511481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197166255710 + 197166255711.

It is an arithmetic number, because the mean of its divisors is an integer number (197166255711).

Almost surely, 2^394332511421 is an apocalyptic number.

It is an amenable number.

394332511421 is a deficient number, since it is larger than the sum of its proper divisors (1).

394332511421 is an equidigital number, since it uses as much as digits as its factorization.

394332511421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 38.

The spelling of 394332511421 in words is "three hundred ninety-four billion, three hundred thirty-two million, five hundred eleven thousand, four hundred twenty-one".