32991521 has 2 divisors, whose sum is σ = 32991522. Its totient is φ = 32991520.

The previous prime is 32991503. The next prime is 32991523. The reversal of 32991521 is 12519923.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23658496 + 9333025 = 4864^2 + 3055^2 .

It is a cyclic number.

It is not a de Polignac number, because 32991521 - 2¹⁰ = 32990497 is a prime.

Together with 32991523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (32991523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16495760 + 16495761.

It is an arithmetic number, because the mean of its divisors is an integer number (16495761).

Almost surely, 2^32991521 is an apocalyptic number.

It is an amenable number.

32991521 is a deficient number, since it is larger than the sum of its proper divisors (1).

32991521 is an equidigital number, since it uses as much as digits as its factorization.

32991521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4860, while the sum is 32.

The square root of 32991521 is about 5743.8245969041. The cubic root of 32991521 is about 320.7259592489.

The spelling of 32991521 in words is "thirty-two million, nine hundred ninety-one thousand, five hundred twenty-one".