1965381497977 has 4 divisors (see below), whose sum is σ = 2013317632116. Its totient is φ = 1917445363840.

The previous prime is 1965381497941. The next prime is 1965381498049. The reversal of 1965381497977 is 7797941835691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 133538354041 + 1831843143936 = 365429^2 + 1353456^2 .

It is a cyclic number.

It is not a de Polignac number, because 1965381497977 - 2²³ = 1965373109369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1965381497927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23968067008 + ... + 23968067089.

It is an arithmetic number, because the mean of its divisors is an integer number (503329408029).

Almost surely, 2^{1965381497977} is an apocalyptic number.

It is an amenable number.

1965381497977 is a deficient number, since it is larger than the sum of its proper divisors (47936134139).

1965381497977 is an equidigital number, since it uses as much as digits as its factorization.

1965381497977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47936134138.

The product of its digits is 720135360, while the sum is 76.

The spelling of 1965381497977 in words is "one trillion, nine hundred sixty-five billion, three hundred eighty-one million, four hundred ninety-seven thousand, nine hundred seventy-seven".