201321001987 has 4 divisors (see below), whose sum is σ = 230081145136. Its totient is φ = 172560858840.

The previous prime is 201321001979. The next prime is 201321002021. The reversal of 201321001987 is 789100123102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 201321001987 - 2³ = 201321001979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201321031987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14380071564 + ... + 14380071577.

It is an arithmetic number, because the mean of its divisors is an integer number (57520286284).

Almost surely, 2^201321001987 is an apocalyptic number.

201321001987 is a deficient number, since it is larger than the sum of its proper divisors (28760143149).

201321001987 is an equidigital number, since it uses as much as digits as its factorization.

201321001987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28760143148.

The product of its (nonzero) digits is 6048, while the sum is 34.

The spelling of 201321001987 in words is "two hundred one billion, three hundred twenty-one million, one thousand, nine hundred eighty-seven".