199620410521 has 27 divisors (see below), whose sum is σ = 235348979391. Its totient is φ = 168821904384.

The previous prime is 199620410503. The next prime is 199620410527. The reversal of 199620410521 is 125014026991.

The square root of 199620410521 is 446789.

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

It can be written as a sum of positive squares in only one way, i.e., 78098450521 + 121521960000 = 279461^2 + 348600^2 .

It is not a de Polignac number, because 199620410521 - 2¹⁷ = 199620279449 is a prime.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199620410527) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 259584025 + ... + 259584793.

Almost surely, 2^199620410521 is an apocalyptic number.

199620410521 is the 446789-th square number.

199620410521 is the 223395-th centered octagonal number.

It is an amenable number.

199620410521 is a deficient number, since it is larger than the sum of its proper divisors (35728568870).

199620410521 is an frugal number, since it uses more digits than its factorization.

199620410521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1718 (or 859 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 40.

The spelling of 199620410521 in words is "one hundred ninety-nine billion, six hundred twenty million, four hundred ten thousand, five hundred twenty-one".