1201661939 has 2 divisors, whose sum is σ = 1201661940. Its totient is φ = 1201661938.

The previous prime is 1201661921. The next prime is 1201661941. The reversal of 1201661939 is 9391661021.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1201661939 is a prime.

Together with 1201661941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1201661239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600830969 + 600830970.

It is an arithmetic number, because the mean of its divisors is an integer number (600830970).

Almost surely, 2^1201661939 is an apocalyptic number.

1201661939 is a deficient number, since it is larger than the sum of its proper divisors (1).

1201661939 is an equidigital number, since it uses as much as digits as its factorization.

1201661939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 1201661939 is about 34664.9958748014. The cubic root of 1201661939 is about 1063.1489189157.

The spelling of 1201661939 in words is "one billion, two hundred one million, six hundred sixty-one thousand, nine hundred thirty-nine".