20251481 has 4 divisors (see below), whose sum is σ = 20277264. Its totient is φ = 20225700.

The previous prime is 20251457. The next prime is 20251493. The reversal of 20251481 is 18415202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20251481 - 2¹⁰ = 20250457 is a prime.

It is a super-2 number, since 2×20251481² = 820244965386722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20251081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11675 + ... + 13296.

It is an arithmetic number, because the mean of its divisors is an integer number (5069316).

Almost surely, 2^20251481 is an apocalyptic number.

It is an amenable number.

20251481 is a deficient number, since it is larger than the sum of its proper divisors (25783).

20251481 is an equidigital number, since it uses as much as digits as its factorization.

20251481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25782.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 20251481 is about 4500.1645525469. The cubic root of 20251481 is about 272.5747335915.

Adding to 20251481 its reverse (18415202), we get a palindrome (38666683).

The spelling of 20251481 in words is "twenty million, two hundred fifty-one thousand, four hundred eighty-one".