921248521 has 2 divisors, whose sum is σ = 921248522. Its totient is φ = 921248520.

The previous prime is 921248443. The next prime is 921248527. The reversal of 921248521 is 125842129.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 879774921 + 41473600 = 29661^2 + 6440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-921248521 is a prime.

It is not a weakly prime, because it can be changed into another prime (921248527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460624260 + 460624261.

It is an arithmetic number, because the mean of its divisors is an integer number (460624261).

Almost surely, 2^921248521 is an apocalyptic number.

It is an amenable number.

921248521 is a deficient number, since it is larger than the sum of its proper divisors (1).

921248521 is an equidigital number, since it uses as much as digits as its factorization.

921248521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 34.

The square root of 921248521 is about 30352.0760574956. The cubic root of 921248521 is about 973.0285902351.

The spelling of 921248521 in words is "nine hundred twenty-one million, two hundred forty-eight thousand, five hundred twenty-one".