20131549 has 2 divisors, whose sum is σ = 20131550. Its totient is φ = 20131548.

The previous prime is 20131547. The next prime is 20131561. The reversal of 20131549 is 94513102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17935225 + 2196324 = 4235^2 + 1482^2 .

It is a cyclic number.

It is not a de Polignac number, because 20131549 - 2¹ = 20131547 is a prime.

Together with 20131547, 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 (20131541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10065774 + 10065775.

It is an arithmetic number, because the mean of its divisors is an integer number (10065775).

Almost surely, 2^20131549 is an apocalyptic number.

It is an amenable number.

20131549 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131549 is an equidigital number, since it uses as much as digits as its factorization.

20131549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20131549 is about 4486.8194748619. The cubic root of 20131549 is about 272.0355931291.

The spelling of 20131549 in words is "twenty million, one hundred thirty-one thousand, five hundred forty-nine".