19615801871261 has 2 divisors, whose sum is σ = 19615801871262. Its totient is φ = 19615801871260.

The previous prime is 19615801871227. The next prime is 19615801871279. The reversal of 19615801871261 is 16217810851691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17427443795161 + 2188358076100 = 4174619^2 + 1479310^2 .

It is a cyclic number.

It is not a de Polignac number, because 19615801871261 - 2²⁶ = 19615734762397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19615801871197 and 19615801871206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19615801871201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9807900935630 + 9807900935631.

It is an arithmetic number, because the mean of its divisors is an integer number (9807900935631).

Almost surely, 2^{19615801871261} is an apocalyptic number.

It is an amenable number.

19615801871261 is a deficient number, since it is larger than the sum of its proper divisors (1).

19615801871261 is an equidigital number, since it uses as much as digits as its factorization.

19615801871261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1451520, while the sum is 56.

The spelling of 19615801871261 in words is "nineteen trillion, six hundred fifteen billion, eight hundred one million, eight hundred seventy-one thousand, two hundred sixty-one".