20047251 has 16 divisors (see below), whose sum is σ = 30612224. Its totient is φ = 11431584.

The previous prime is 20047241. The next prime is 20047253. The reversal of 20047251 is 15274002.

It is not a de Polignac number, because 20047251 - 2⁷ = 20047123 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20047253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15921 + ... + 17133.

It is an arithmetic number, because the mean of its divisors is an integer number (1913264).

Almost surely, 2^20047251 is an apocalyptic number.

20047251 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20047251 is a deficient number, since it is larger than the sum of its proper divisors (10564973).

20047251 is a wasteful number, since it uses less digits than its factorization.

20047251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2010.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 20047251 is about 4477.4156608472. The cubic root of 20047251 is about 271.6553584480.

The spelling of 20047251 in words is "twenty million, forty-seven thousand, two hundred fifty-one".