1201971989 has 2 divisors, whose sum is σ = 1201971990. Its totient is φ = 1201971988.

The previous prime is 1201971941. The next prime is 1201972003. The reversal of 1201971989 is 9891791021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 843437764 + 358534225 = 29042^2 + 18935^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1201971989 is a prime.

It is a super-3 number, since 3×1201971989³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1201971919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600985994 + 600985995.

It is an arithmetic number, because the mean of its divisors is an integer number (600985995).

Almost surely, 2^1201971989 is an apocalyptic number.

It is an amenable number.

1201971989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1201971989 is an equidigital number, since it uses as much as digits as its factorization.

1201971989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 47.

The square root of 1201971989 is about 34669.4676769056. The cubic root of 1201971989 is about 1063.2403481177.

The spelling of 1201971989 in words is "one billion, two hundred one million, nine hundred seventy-one thousand, nine hundred eighty-nine".