19812213893 has 2 divisors, whose sum is σ = 19812213894. Its totient is φ = 19812213892.

The previous prime is 19812213871. The next prime is 19812213901. The reversal of 19812213893 is 39831221891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19487601604 + 324612289 = 139598^2 + 18017^2 .

It is a cyclic number.

It is not a de Polignac number, because 19812213893 - 2¹⁸ = 19811951749 is a prime.

It is a super-3 number, since 3×19812213893³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19812213803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9906106946 + 9906106947.

It is an arithmetic number, because the mean of its divisors is an integer number (9906106947).

Almost surely, 2^19812213893 is an apocalyptic number.

It is an amenable number.

19812213893 is a deficient number, since it is larger than the sum of its proper divisors (1).

19812213893 is an equidigital number, since it uses as much as digits as its factorization.

19812213893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 47.

The spelling of 19812213893 in words is "nineteen billion, eight hundred twelve million, two hundred thirteen thousand, eight hundred ninety-three".