407491681 has 2 divisors, whose sum is σ = 407491682. Its totient is φ = 407491680.

The previous prime is 407491627. The next prime is 407491729. The reversal of 407491681 is 186194704.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218566656 + 188925025 = 14784^2 + 13745^2 .

It is a cyclic number.

It is not a de Polignac number, because 407491681 - 2¹⁵ = 407458913 is a prime.

It is a super-3 number, since 3×407491681³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (407491481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203745840 + 203745841.

It is an arithmetic number, because the mean of its divisors is an integer number (203745841).

Almost surely, 2^407491681 is an apocalyptic number.

It is an amenable number.

407491681 is a deficient number, since it is larger than the sum of its proper divisors (1).

407491681 is an equidigital number, since it uses as much as digits as its factorization.

407491681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 407491681 is about 20186.4231849033. The cubic root of 407491681 is about 741.3778086393.

The spelling of 407491681 in words is "four hundred seven million, four hundred ninety-one thousand, six hundred eighty-one".