32491721987 has 4 divisors (see below), whose sum is σ = 32498372760. Its totient is φ = 32485071216.

The previous prime is 32491721959. The next prime is 32491721993. The reversal of 32491721987 is 78912719423.

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-32491721987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (32491724987) 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, 3318053 + ... + 3327830.

It is an arithmetic number, because the mean of its divisors is an integer number (8124593190).

Almost surely, 2^32491721987 is an apocalyptic number.

32491721987 is a deficient number, since it is larger than the sum of its proper divisors (6650773).

32491721987 is an equidigital number, since it uses as much as digits as its factorization.

32491721987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6650772.

The product of its digits is 1524096, while the sum is 53.

The spelling of 32491721987 in words is "thirty-two billion, four hundred ninety-one million, seven hundred twenty-one thousand, nine hundred eighty-seven".