18797521 has 2 divisors, whose sum is σ = 18797522. Its totient is φ = 18797520.

The previous prime is 18797503. The next prime is 18797531. The reversal of 18797521 is 12579781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10595025 + 8202496 = 3255^2 + 2864^2 .

It is a cyclic number.

It is not a de Polignac number, because 18797521 - 2¹¹ = 18795473 is a prime.

It is not a weakly prime, because it can be changed into another prime (18797531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9398760 + 9398761.

It is an arithmetic number, because the mean of its divisors is an integer number (9398761).

Almost surely, 2^18797521 is an apocalyptic number.

It is an amenable number.

18797521 is a deficient number, since it is larger than the sum of its proper divisors (1).

18797521 is an equidigital number, since it uses as much as digits as its factorization.

18797521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 40.

The square root of 18797521 is about 4335.6107989532. The cubic root of 18797521 is about 265.8888911655. Note that the first 4 decimals are identical.

The spelling of 18797521 in words is "eighteen million, seven hundred ninety-seven thousand, five hundred twenty-one".