20577010643721 has 63 divisors (see below), whose sum is σ = 35889861858903. Its totient is φ = 11757801888000.

The previous prime is 20577010643677. The next prime is 20577010643729. The reversal of 20577010643721 is 12734601077502.

The square root of 20577010643721 is 4536189.

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

20577010643721 is a `hidden beast` number, since 2 + 0 + 577 + 0 + 1 + 0 + 6 + 4 + 3 + 72 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5535954885321 + 15041055758400 = 2352861^2 + 3878280^2 .

It is a tau number, because it is divible by the number of its divisors (63).

It is not a de Polignac number, because 20577010643721 - 2¹¹ = 20577010641673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20577010643729) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 857327721 + ... + 857351721.

Almost surely, 2^{20577010643721} is an apocalyptic number.

20577010643721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20577010643721 is the 4536189-th square number.

20577010643721 is the 2268095-th centered octagonal number.

It is an amenable number.

20577010643721 is a deficient number, since it is larger than the sum of its proper divisors (15312851215182).

20577010643721 is an frugal number, since it uses more digits than its factorization.

20577010643721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48034 (or 24011 counting only the distinct ones).

The product of its (nonzero) digits is 493920, while the sum is 45.

The spelling of 20577010643721 in words is "twenty trillion, five hundred seventy-seven billion, ten million, six hundred forty-three thousand, seven hundred twenty-one".