20973219628581 has 24 divisors (see below), whose sum is σ = 33071869512864. Its totient is φ = 12702134585760.

The previous prime is 20973219628567. The next prime is 20973219628607. The reversal of 20973219628581 is 18582691237902.

20973219628581 is a `hidden beast` number, since 2 + 0 + 9 + 7 + 3 + 21 + 9 + 6 + 28 + 581 = 666.

It is not a de Polignac number, because 20973219628581 - 2⁹ = 20973219628069 is a prime.

It is a super-2 number, since 2×20973219628581² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20973219628531) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74088126 + ... + 74370671.

It is an arithmetic number, because the mean of its divisors is an integer number (1377994563036).

Almost surely, 2^{20973219628581} is an apocalyptic number.

It is an amenable number.

20973219628581 is a deficient number, since it is larger than the sum of its proper divisors (12098649884283).

20973219628581 is a wasteful number, since it uses less digits than its factorization.

20973219628581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148460241 (or 148460238 counting only the distinct ones).

The product of its (nonzero) digits is 26127360, while the sum is 63.

The spelling of 20973219628581 in words is "twenty trillion, nine hundred seventy-three billion, two hundred nineteen million, six hundred twenty-eight thousand, five hundred eighty-one".