405660091 has 4 divisors (see below), whose sum is σ = 419648400. Its totient is φ = 391671784.

The previous prime is 405660083. The next prime is 405660097. The reversal of 405660091 is 190066504.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 405660091 - 2³ = 405660083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (405660097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6994111 + ... + 6994168.

It is an arithmetic number, because the mean of its divisors is an integer number (104912100).

Almost surely, 2^405660091 is an apocalyptic number.

405660091 is a deficient number, since it is larger than the sum of its proper divisors (13988309).

405660091 is a wasteful number, since it uses less digits than its factorization.

405660091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13988308.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 405660091 is about 20141.0052132459. The cubic root of 405660091 is about 740.2653607603.

The spelling of 405660091 in words is "four hundred five million, six hundred sixty thousand, ninety-one".