385645621 has 2 divisors, whose sum is σ = 385645622. Its totient is φ = 385645620.

The previous prime is 385645553. The next prime is 385645643. The reversal of 385645621 is 126546583.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 326524900 + 59120721 = 18070^2 + 7689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-385645621 is a prime.

It is a super-4 number, since 4×385645621⁴ (a number of 35 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385645021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192822810 + 192822811.

It is an arithmetic number, because the mean of its divisors is an integer number (192822811).

Almost surely, 2^385645621 is an apocalyptic number.

It is an amenable number.

385645621 is a deficient number, since it is larger than the sum of its proper divisors (1).

385645621 is an equidigital number, since it uses as much as digits as its factorization.

385645621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 40.

The square root of 385645621 is about 19637.8619253726. The cubic root of 385645621 is about 727.8850532248.

The spelling of 385645621 in words is "three hundred eighty-five million, six hundred forty-five thousand, six hundred twenty-one".