19781011465 has 32 divisors (see below), whose sum is σ = 24328362240. Its totient is φ = 15437205504.

The previous prime is 19781011463. The next prime is 19781011469. The reversal of 19781011465 is 56411018791.

It is a cyclic number.

It is not a de Polignac number, because 19781011465 - 2¹ = 19781011463 is a prime.

It is a super-2 number, since 2×19781011465² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (19781011463) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9806137 + ... + 9808153.

It is an arithmetic number, because the mean of its divisors is an integer number (760261320).

Almost surely, 2^19781011465 is an apocalyptic number.

It is an amenable number.

19781011465 is a deficient number, since it is larger than the sum of its proper divisors (4547350775).

19781011465 is a wasteful number, since it uses less digits than its factorization.

19781011465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2401.

The product of its (nonzero) digits is 60480, while the sum is 43.

The spelling of 19781011465 in words is "nineteen billion, seven hundred eighty-one million, eleven thousand, four hundred sixty-five".