20154881 has 2 divisors, whose sum is σ = 20154882. Its totient is φ = 20154880.

The previous prime is 20154859. The next prime is 20154887. The reversal of 20154881 is 18845102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14938225 + 5216656 = 3865^2 + 2284^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20154881 is a prime.

It is a super-2 number, since 2×20154881² = 812438456248322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20154887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077440 + 10077441.

It is an arithmetic number, because the mean of its divisors is an integer number (10077441).

Almost surely, 2^20154881 is an apocalyptic number.

It is an amenable number.

20154881 is a deficient number, since it is larger than the sum of its proper divisors (1).

20154881 is an equidigital number, since it uses as much as digits as its factorization.

20154881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 20154881 is about 4489.4187819806. The cubic root of 20154881 is about 272.1406468763.

Adding to 20154881 its reverse (18845102), we get a palindrome (38999983).

The spelling of 20154881 in words is "twenty million, one hundred fifty-four thousand, eight hundred eighty-one".