201999989453 has 2 divisors, whose sum is σ = 201999989454. Its totient is φ = 201999989452.

The previous prime is 201999989449. The next prime is 201999989473. The reversal of 201999989453 is 354989999102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136797899044 + 65202090409 = 369862^2 + 255347^2 .

It is a cyclic number.

It is not a de Polignac number, because 201999989453 - 2² = 201999989449 is a prime.

It is a super-2 number, since 2×201999989453² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201999989473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100999994726 + 100999994727.

It is an arithmetic number, because the mean of its divisors is an integer number (100999994727).

Almost surely, 2^201999989453 is an apocalyptic number.

It is an amenable number.

201999989453 is a deficient number, since it is larger than the sum of its proper divisors (1).

201999989453 is an equidigital number, since it uses as much as digits as its factorization.

201999989453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56687040, while the sum is 68.

The spelling of 201999989453 in words is "two hundred one billion, nine hundred ninety-nine million, nine hundred eighty-nine thousand, four hundred fifty-three".