21571389539001 has 27 divisors (see below), whose sum is σ = 31210423423023. Its totient is φ = 14357081491200.

The previous prime is 21571389538969. The next prime is 21571389539027. The reversal of 21571389539001 is 10093598317512.

The square root of 21571389539001 is 4644501.

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

21571389539001 is a `hidden beast` number, since 2 + 1 + 5 + 71 + 38 + 9 + 539 + 0 + 0 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21517528412601 + 53861126400 = 4638699^2 + 232080^2 .

It is not a de Polignac number, because 21571389539001 - 2⁵ = 21571389538969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21571389539201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 13473696601 + ... + 13473698201.

Almost surely, 2^{21571389539001} is an apocalyptic number.

21571389539001 is the 4644501-st square number.

21571389539001 is the 2322251-st centered octagonal number.

It is an amenable number.

21571389539001 is a deficient number, since it is larger than the sum of its proper divisors (9639033884022).

21571389539001 is an frugal number, since it uses more digits than its factorization.

21571389539001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5142 (or 2571 counting only the distinct ones).

The product of its (nonzero) digits is 2041200, while the sum is 54.

The spelling of 21571389539001 in words is "twenty-one trillion, five hundred seventy-one billion, three hundred eighty-nine million, five hundred thirty-nine thousand, one".