1971653779 has 2 divisors, whose sum is σ = 1971653780. Its totient is φ = 1971653778.

The previous prime is 1971653753. The next prime is 1971653923. The reversal of 1971653779 is 9773561791.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1971653779 - 2¹⁹ = 1971129491 is a prime.

It is not a weakly prime, because it can be changed into another prime (1971653279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985826889 + 985826890.

It is an arithmetic number, because the mean of its divisors is an integer number (985826890).

Almost surely, 2^1971653779 is an apocalyptic number.

1971653779 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971653779 is an equidigital number, since it uses as much as digits as its factorization.

1971653779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2500470, while the sum is 55.

The square root of 1971653779 is about 44403.3081988268. The cubic root of 1971653779 is about 1253.9403719102.

The spelling of 1971653779 in words is "one billion, nine hundred seventy-one million, six hundred fifty-three thousand, seven hundred seventy-nine".