21199068801 has 9 divisors (see below), whose sum is σ = 30621508099. Its totient is φ = 14132421336.

The previous prime is 21199068791. The next prime is 21199068823. The reversal of 21199068801 is 10886099112.

The square root of 21199068801 is 145599.

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., 18751194225 + 2447874576 = 136935^2 + 49476^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 21199068801 - 2⁵ = 21199068769 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21199068851) 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, 412531 + ... + 461063.

Almost surely, 2^21199068801 is an apocalyptic number.

21199068801 is the 145599-th square number.

21199068801 is the 72800-th centered octagonal number.

It is an amenable number.

21199068801 is a deficient number, since it is larger than the sum of its proper divisors (9422439298).

21199068801 is an frugal number, since it uses more digits than its factorization.

21199068801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97072 (or 48536 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 45.

The spelling of 21199068801 in words is "twenty-one billion, one hundred ninety-nine million, sixty-eight thousand, eight hundred one".