210863721601 has 9 divisors (see below), whose sum is σ = 228338186499. Its totient is φ = 194637924936.

The previous prime is 210863721589. The next prime is 210863721643. The reversal of 210863721601 is 106127368012.

The square root of 210863721601 is 459199.

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., 31192858225 + 179670863376 = 176615^2 + 423876^2 .

It is not a de Polignac number, because 210863721601 - 2⁵ = 210863721569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210863521601) 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, 5951926 + ... + 5987248.

It is an arithmetic number, because the mean of its divisors is an integer number (25370909611).

Almost surely, 2^210863721601 is an apocalyptic number.

210863721601 is the 459199-th square number.

210863721601 is the 229600-th centered octagonal number.

It is an amenable number.

210863721601 is a deficient number, since it is larger than the sum of its proper divisors (17474464898).

210863721601 is an frugal number, since it uses more digits than its factorization.

210863721601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70672 (or 35336 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The spelling of 210863721601 in words is "two hundred ten billion, eight hundred sixty-three million, seven hundred twenty-one thousand, six hundred one".