1901221213 has 2 divisors, whose sum is σ = 1901221214. Its totient is φ = 1901221212.

The previous prime is 1901221211. The next prime is 1901221229. The reversal of 1901221213 is 3121221091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1280065284 + 621155929 = 35778^2 + 24923^2 .

It is a cyclic number.

It is not a de Polignac number, because 1901221213 - 2¹ = 1901221211 is a prime.

It is a super-2 number, since 2×1901221213² = 7229284201522382738, which contains 22 as substring.

Together with 1901221211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1901221211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950610606 + 950610607.

It is an arithmetic number, because the mean of its divisors is an integer number (950610607).

Almost surely, 2^1901221213 is an apocalyptic number.

It is an amenable number.

1901221213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1901221213 is an equidigital number, since it uses as much as digits as its factorization.

1901221213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 1901221213 is about 43602.9954590278. The cubic root of 1901221213 is about 1238.8276321694.

The spelling of 1901221213 in words is "one billion, nine hundred one million, two hundred twenty-one thousand, two hundred thirteen".