921242521 has 2 divisors, whose sum is σ = 921242522. Its totient is φ = 921242520.

The previous prime is 921242467. The next prime is 921242551. The reversal of 921242521 is 125242129.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 899340121 + 21902400 = 29989^2 + 4680^2 .

It is a cyclic number.

It is not a de Polignac number, because 921242521 - 2¹¹ = 921240473 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 921242521.

It is not a weakly prime, because it can be changed into another prime (921242551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460621260 + 460621261.

It is an arithmetic number, because the mean of its divisors is an integer number (460621261).

Almost surely, 2^921242521 is an apocalyptic number.

It is an amenable number.

921242521 is a deficient number, since it is larger than the sum of its proper divisors (1).

921242521 is an equidigital number, since it uses as much as digits as its factorization.

921242521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 28.

The square root of 921242521 is about 30351.9772173083. The cubic root of 921242521 is about 973.0264778177.

The spelling of 921242521 in words is "nine hundred twenty-one million, two hundred forty-two thousand, five hundred twenty-one".