19657093381 has 2 divisors, whose sum is σ = 19657093382. Its totient is φ = 19657093380.

The previous prime is 19657093369. The next prime is 19657093409. The reversal of 19657093381 is 18339075691.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17679957156 + 1977136225 = 132966^2 + 44465^2 .

It is a cyclic number.

It is not a de Polignac number, because 19657093381 - 2⁹ = 19657092869 is a prime.

It is a super-2 number, since 2×19657093381² (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 (19657093301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9828546690 + 9828546691.

It is an arithmetic number, because the mean of its divisors is an integer number (9828546691).

Almost surely, 2^19657093381 is an apocalyptic number.

It is an amenable number.

19657093381 is a deficient number, since it is larger than the sum of its proper divisors (1).

19657093381 is an equidigital number, since it uses as much as digits as its factorization.

19657093381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1224720, while the sum is 52.

The spelling of 19657093381 in words is "nineteen billion, six hundred fifty-seven million, ninety-three thousand, three hundred eighty-one".