2781381061505 has 8 divisors (see below), whose sum is σ = 3368277983400. Its totient is φ = 2204691042816.

The previous prime is 2781381061429. The next prime is 2781381061519. The reversal of 2781381061505 is 5051601831872.

It can be written as a sum of positive squares in 4 ways, for example, as 895296332401 + 1886084729104 = 946201^2 + 1373348^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2781381061505 - 2¹⁸ = 2781380799361 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2781381061505.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2551725200 + ... + 2551726289.

It is an arithmetic number, because the mean of its divisors is an integer number (421034747925).

Almost surely, 2^{2781381061505} is an apocalyptic number.

It is an amenable number.

2781381061505 is a deficient number, since it is larger than the sum of its proper divisors (586896921895).

2781381061505 is a wasteful number, since it uses less digits than its factorization.

2781381061505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5103451603.

The product of its (nonzero) digits is 403200, while the sum is 47.

The spelling of 2781381061505 in words is "two trillion, seven hundred eighty-one billion, three hundred eighty-one million, sixty-one thousand, five hundred five".