201021120691 has 2 divisors, whose sum is σ = 201021120692. Its totient is φ = 201021120690.

The previous prime is 201021120637. The next prime is 201021120793. The reversal of 201021120691 is 196021120102.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 201021120691 - 2¹⁷ = 201020989619 is a prime.

It is not a weakly prime, because it can be changed into another prime (201021120631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100510560345 + 100510560346.

It is an arithmetic number, because the mean of its divisors is an integer number (100510560346).

Almost surely, 2^201021120691 is an apocalyptic number.

201021120691 is a deficient number, since it is larger than the sum of its proper divisors (1).

201021120691 is an equidigital number, since it uses as much as digits as its factorization.

201021120691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

Adding to 201021120691 its reverse (196021120102), we get a palindrome (397042240793).

The spelling of 201021120691 in words is "two hundred one billion, twenty-one million, one hundred twenty thousand, six hundred ninety-one".