2381981778465 has 16 divisors (see below), whose sum is σ = 3812014320000. Its totient is φ = 1270109123712.

The previous prime is 2381981778457. The next prime is 2381981778479. The reversal of 2381981778465 is 5648771891832.

It is not a de Polignac number, because 2381981778465 - 2³ = 2381981778457 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2381981778465.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17502340 + ... + 17637909.

It is an arithmetic number, because the mean of its divisors is an integer number (238250895000).

Almost surely, 2^{2381981778465} is an apocalyptic number.

It is an amenable number.

2381981778465 is a deficient number, since it is larger than the sum of its proper divisors (1430032541535).

2381981778465 is a wasteful number, since it uses less digits than its factorization.

2381981778465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35144776.

The product of its digits is 162570240, while the sum is 69.

The spelling of 2381981778465 in words is "two trillion, three hundred eighty-one billion, nine hundred eighty-one million, seven hundred seventy-eight thousand, four hundred sixty-five".