1957887691 has 2 divisors, whose sum is σ = 1957887692. Its totient is φ = 1957887690.

The previous prime is 1957887649. The next prime is 1957887709. The reversal of 1957887691 is 1967887591.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1957887691 - 2¹³ = 1957879499 is a prime.

It is a super-2 number, since 2×1957887691² = 7666648421138622962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1957887641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 978943845 + 978943846.

It is an arithmetic number, because the mean of its divisors is an integer number (978943846).

Almost surely, 2^1957887691 is an apocalyptic number.

1957887691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1957887691 is an equidigital number, since it uses as much as digits as its factorization.

1957887691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7620480, while the sum is 61.

The square root of 1957887691 is about 44248.0247129745. The cubic root of 1957887691 is about 1251.0152159926.

The spelling of 1957887691 in words is "one billion, nine hundred fifty-seven million, eight hundred eighty-seven thousand, six hundred ninety-one".