1900101221 has 2 divisors, whose sum is σ = 1900101222. Its totient is φ = 1900101220.

The previous prime is 1900101211. The next prime is 1900101223. The reversal of 1900101221 is 1221010091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1549288321 + 350812900 = 39361^2 + 18730^2 .

It is a cyclic number.

It is not a de Polignac number, because 1900101221 - 2¹⁰ = 1900100197 is a prime.

It is a super-2 number, since 2×1900101221² = 7220769300091381682, which contains 22 as substring.

Together with 1900101223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1900101221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1900101223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950050610 + 950050611.

It is an arithmetic number, because the mean of its divisors is an integer number (950050611).

Almost surely, 2^1900101221 is an apocalyptic number.

It is an amenable number.

1900101221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1900101221 is an equidigital number, since it uses as much as digits as its factorization.

1900101221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 1900101221 is about 43590.1505044431. The cubic root of 1900101221 is about 1238.5843237164.

The spelling of 1900101221 in words is "one billion, nine hundred million, one hundred one thousand, two hundred twenty-one".