19461006781 has 2 divisors, whose sum is σ = 19461006782. Its totient is φ = 19461006780.

The previous prime is 19461006737. The next prime is 19461006797. The reversal of 19461006781 is 18760016491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18730385881 + 730620900 = 136859^2 + 27030^2 .

It is a cyclic number.

It is not a de Polignac number, because 19461006781 - 2⁹ = 19461006269 is a prime.

It is a super-2 number, since 2×19461006781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19461006701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9730503390 + 9730503391.

It is an arithmetic number, because the mean of its divisors is an integer number (9730503391).

Almost surely, 2^19461006781 is an apocalyptic number.

It is an amenable number.

19461006781 is a deficient number, since it is larger than the sum of its proper divisors (1).

19461006781 is an equidigital number, since it uses as much as digits as its factorization.

19461006781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 43.

The spelling of 19461006781 in words is "nineteen billion, four hundred sixty-one million, six thousand, seven hundred eighty-one".