201989031779 has 2 divisors, whose sum is σ = 201989031780. Its totient is φ = 201989031778.

The previous prime is 201989031763. The next prime is 201989031799. The reversal of 201989031779 is 977130989102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 201989031779 - 2⁴ = 201989031763 is a prime.

It is not a weakly prime, because it can be changed into another prime (201989031719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100994515889 + 100994515890.

It is an arithmetic number, because the mean of its divisors is an integer number (100994515890).

Almost surely, 2^201989031779 is an apocalyptic number.

201989031779 is a deficient number, since it is larger than the sum of its proper divisors (1).

201989031779 is an equidigital number, since it uses as much as digits as its factorization.

201989031779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1714608, while the sum is 56.

The spelling of 201989031779 in words is "two hundred one billion, nine hundred eighty-nine million, thirty-one thousand, seven hundred seventy-nine".