405232991 has 4 divisors (see below), whose sum is σ = 416185272. Its totient is φ = 394280712.

The previous prime is 405232973. The next prime is 405232999. The reversal of 405232991 is 199232504.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-405232991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405232999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5476085 + ... + 5476158.

It is an arithmetic number, because the mean of its divisors is an integer number (104046318).

Almost surely, 2^405232991 is an apocalyptic number.

405232991 is a deficient number, since it is larger than the sum of its proper divisors (10952281).

405232991 is a wasteful number, since it uses less digits than its factorization.

405232991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10952280.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 405232991 is about 20130.3996731312. The cubic root of 405232991 is about 740.0054729325.

The spelling of 405232991 in words is "four hundred five million, two hundred thirty-two thousand, nine hundred ninety-one".