32400991 has 16 divisors (see below), whose sum is σ = 37739520. Its totient is φ = 27246240.

The previous prime is 32400961. The next prime is 32401003. The reversal of 32400991 is 19900423.

It is a happy number.

It is not a de Polignac number, because 32400991 - 2⁹ = 32400479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (32400941) 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 15 ways as a sum of consecutive naturals, for example, 135450 + ... + 135688.

It is an arithmetic number, because the mean of its divisors is an integer number (2358720).

Almost surely, 2^32400991 is an apocalyptic number.

32400991 is a deficient number, since it is larger than the sum of its proper divisors (5338529).

32400991 is a wasteful number, since it uses less digits than its factorization.

32400991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 32400991 is about 5692.1868381142. The cubic root of 32400991 is about 318.8008210138.

The spelling of 32400991 in words is "thirty-two million, four hundred thousand, nine hundred ninety-one".