20879961001 has 9 divisors (see below), whose sum is σ = 21004826103. Its totient is φ = 20755836360.

The previous prime is 20879960957. The next prime is 20879961007. The reversal of 20879961001 is 10016997802.

The square root of 20879961001 is 144499.

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., 19446581401 + 1433379600 = 139451^2 + 37860^2 .

It is not a de Polignac number, because 20879961001 - 2⁷ = 20879960873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20879961007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 33089956 + ... + 33090586.

It is an arithmetic number, because the mean of its divisors is an integer number (2333869567).

Almost surely, 2^20879961001 is an apocalyptic number.

20879961001 is the 144499-th square number.

20879961001 is the 72250-th centered octagonal number.

It is an amenable number.

20879961001 is a deficient number, since it is larger than the sum of its proper divisors (124865102).

20879961001 is an frugal number, since it uses more digits than its factorization.

20879961001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1720 (or 860 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 43.

The spelling of 20879961001 in words is "twenty billion, eight hundred seventy-nine million, nine hundred sixty-one thousand, one".