1965381497978 has 8 divisors (see below), whose sum is σ = 2957372160372. Its totient is φ = 979590777856.

The previous prime is 1965381497941. The next prime is 1965381498049. The reversal of 1965381497978 is 8797941835691.

It can be written as a sum of positive squares in 2 ways, for example, as 1720260458569 + 245121039409 = 1311587^2 + 495097^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 1965381497899 and 1965381497908.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1549984775 + ... + 1549986042.

Almost surely, 2^{1965381497978} is an apocalyptic number.

1965381497978 is a deficient number, since it is larger than the sum of its proper divisors (991990662394).

1965381497978 is a wasteful number, since it uses less digits than its factorization.

1965381497978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3099971136.

The product of its digits is 823011840, while the sum is 77.

The spelling of 1965381497978 in words is "one trillion, nine hundred sixty-five billion, three hundred eighty-one million, four hundred ninety-seven thousand, nine hundred seventy-eight".