405981601 has 2 divisors, whose sum is σ = 405981602. Its totient is φ = 405981600.

The previous prime is 405981593. The next prime is 405981617. The reversal of 405981601 is 106189504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 336759201 + 69222400 = 18351^2 + 8320^2 .

It is a cyclic number.

It is not a de Polignac number, because 405981601 - 2³ = 405981593 is a prime.

It is not a weakly prime, because it can be changed into another prime (405921601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202990800 + 202990801.

It is an arithmetic number, because the mean of its divisors is an integer number (202990801).

Almost surely, 2^405981601 is an apocalyptic number.

It is an amenable number.

405981601 is a deficient number, since it is larger than the sum of its proper divisors (1).

405981601 is an equidigital number, since it uses as much as digits as its factorization.

405981601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 405981601 is about 20148.9851109181. The cubic root of 405981601 is about 740.4608773779.

The spelling of 405981601 in words is "four hundred five million, nine hundred eighty-one thousand, six hundred one".