20572381 has 2 divisors, whose sum is σ = 20572382. Its totient is φ = 20572380.

The previous prime is 20572379. The next prime is 20572399. The reversal of 20572381 is 18327502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19660356 + 912025 = 4434^2 + 955^2 .

It is a cyclic number.

It is not a de Polignac number, because 20572381 - 2¹ = 20572379 is a prime.

It is a super-2 number, since 2×20572381² = 846445720018322, which contains 22 as substring.

Together with 20572379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20572301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10286190 + 10286191.

It is an arithmetic number, because the mean of its divisors is an integer number (10286191).

Almost surely, 2^20572381 is an apocalyptic number.

It is an amenable number.

20572381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20572381 is an equidigital number, since it uses as much as digits as its factorization.

20572381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 20572381 is about 4535.6786702764. The cubic root of 20572381 is about 274.0069128204.

Adding to 20572381 its reverse (18327502), we get a palindrome (38899883).

The spelling of 20572381 in words is "twenty million, five hundred seventy-two thousand, three hundred eighty-one".