20100261 has 4 divisors (see below), whose sum is σ = 26800352. Its totient is φ = 13400172.

The previous prime is 20100257. The next prime is 20100263. The reversal of 20100261 is 16200102.

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 not a de Polignac number, because 20100261 - 2² = 20100257 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20100263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3350041 + ... + 3350046.

It is an arithmetic number, because the mean of its divisors is an integer number (6700088).

Almost surely, 2^20100261 is an apocalyptic number.

It is an amenable number.

20100261 is a deficient number, since it is larger than the sum of its proper divisors (6700091).

20100261 is an equidigital number, since it uses as much as digits as its factorization.

20100261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6700090.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 20100261 is about 4483.3314622053. The cubic root of 20100261 is about 271.8945895252.

Adding to 20100261 its reverse (16200102), we get a palindrome (36300363).

The spelling of 20100261 in words is "twenty million, one hundred thousand, two hundred sixty-one".