99221521 has 9 divisors (see below), whose sum is σ = 115502121. Its totient is φ = 84987252.

The previous prime is 99221519. The next prime is 99221533. The reversal of 99221521 is 12512299.

The square root of 99221521 is 9961.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 99221521 - 2¹ = 99221519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (99221321) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 69016 + ... + 70438.

It is an arithmetic number, because the mean of its divisors is an integer number (12833569).

Almost surely, 2^99221521 is an apocalyptic number.

99221521 is the 9961-st square number.

99221521 is the 4981-st centered octagonal number.

It is an amenable number.

99221521 is a deficient number, since it is larger than the sum of its proper divisors (16280600).

99221521 is an frugal number, since it uses more digits than its factorization.

99221521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2860 (or 1430 counting only the distinct ones).

The product of its digits is 3240, while the sum is 31.

The cubic root of 99221521 is about 462.9512844732.

The spelling of 99221521 in words is "ninety-nine million, two hundred twenty-one thousand, five hundred twenty-one".