1901 has 2 divisors, whose sum is σ = 1902. Its totient is φ = 1900.

The previous prime is 1889. The next prime is 1907. The reversal of 1901 is 1091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1225 + 676 = 35^2 + 26^2 .

It is an emirp because it is prime and its reverse (1091) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1061 and 1601.

It is a cyclic number.

It is not a de Polignac number, because 1901 - 2¹⁰ = 877 is a prime.

It is a super-2 number, since 2×1901² = 7227602, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 6, base 8, base 11, base 12 and base 14.

It is a nialpdrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950 + 951.

It is an arithmetic number, because the mean of its divisors is an integer number (951).

1901 is the 20-th centered decagonal number.

It is an amenable number.

1901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1901 is an equidigital number, since it uses as much as digits as its factorization.

1901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9, while the sum is 11.

The square root of 1901 is about 43.6004587132. The cubic root of 1901 is about 12.3877958316.

Adding to 1901 its reverse (1091), we get a palindrome (2992).

It can be divided in two parts, 190 and 1, that added together give a palindrome (191).

The spelling of 1901 in words is "one thousand, nine hundred one".