32391721 has 2 divisors, whose sum is σ = 32391722. Its totient is φ = 32391720.

The previous prime is 32391701. The next prime is 32391743. The reversal of 32391721 is 12719323.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24206400 + 8185321 = 4920^2 + 2861^2 .

It is a cyclic number.

It is not a de Polignac number, because 32391721 - 2⁹ = 32391209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 32391721.

It is not a weakly prime, because it can be changed into another prime (32391701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16195860 + 16195861.

It is an arithmetic number, because the mean of its divisors is an integer number (16195861).

Almost surely, 2^32391721 is an apocalyptic number.

It is an amenable number.

32391721 is a deficient number, since it is larger than the sum of its proper divisors (1).

32391721 is an equidigital number, since it uses as much as digits as its factorization.

32391721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268, while the sum is 28.

The square root of 32391721 is about 5691.3725058197. The cubic root of 32391721 is about 318.7704148914.

The spelling of 32391721 in words is "thirty-two million, three hundred ninety-one thousand, seven hundred twenty-one".