20191281 has 16 divisors (see below), whose sum is σ = 30915840. Its totient is φ = 11592720.

The previous prime is 20191277. The next prime is 20191333. The reversal of 20191281 is 18219102.

It is not a de Polignac number, because 20191281 - 2² = 20191277 is a prime.

It is a super-2 number, since 2×20191281² = 815375656841922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20191231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15475 + ... + 16728.

It is an arithmetic number, because the mean of its divisors is an integer number (1932240).

Almost surely, 2^20191281 is an apocalyptic number.

It is an amenable number.

20191281 is a deficient number, since it is larger than the sum of its proper divisors (10724559).

20191281 is a wasteful number, since it uses less digits than its factorization.

20191281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32236.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 20191281 is about 4493.4709301385. The cubic root of 20191281 is about 272.3043783005.

The spelling of 20191281 in words is "twenty million, one hundred ninety-one thousand, two hundred eighty-one".