1781111913623 has 12 divisors (see below), whose sum is σ = 2071928873520. Its totient is φ = 1526650276032.

The previous prime is 1781111913611. The next prime is 1781111913671. The reversal of 1781111913623 is 3263191111871.

It is not a de Polignac number, because 1781111913623 - 2¹⁰ = 1781111912599 is a prime.

It is a super-2 number, since 2×1781111913623² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781111913023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6364790 + ... + 6638732.

It is an arithmetic number, because the mean of its divisors is an integer number (172660739460).

Almost surely, 2^{1781111913623} is an apocalyptic number.

1781111913623 is a deficient number, since it is larger than the sum of its proper divisors (290816959897).

1781111913623 is a wasteful number, since it uses less digits than its factorization.

1781111913623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406646 (or 406639 counting only the distinct ones).

The product of its digits is 54432, while the sum is 44.

The spelling of 1781111913623 in words is "one trillion, seven hundred eighty-one billion, one hundred eleven million, nine hundred thirteen thousand, six hundred twenty-three".