20361251 has 4 divisors (see below), whose sum is σ = 20695104. Its totient is φ = 20027400.

The previous prime is 20361241. The next prime is 20361281. The reversal of 20361251 is 15216302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20361251 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20361221) 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, 166835 + ... + 166956.

It is an arithmetic number, because the mean of its divisors is an integer number (5173776).

Almost surely, 2^20361251 is an apocalyptic number.

20361251 is a deficient number, since it is larger than the sum of its proper divisors (333853).

20361251 is an equidigital number, since it uses as much as digits as its factorization.

20361251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333852.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20361251 is about 4512.3442909423. The cubic root of 20361251 is about 273.0663294218.

Adding to 20361251 its reverse (15216302), we get a palindrome (35577553).

The spelling of 20361251 in words is "twenty million, three hundred sixty-one thousand, two hundred fifty-one".