15781641732401 has 2 divisors, whose sum is σ = 15781641732402. Its totient is φ = 15781641732400.

The previous prime is 15781641732397. The next prime is 15781641732533. The reversal of 15781641732401 is 10423714618751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11070419546176 + 4711222186225 = 3327224^2 + 2170535^2 .

It is a cyclic number.

It is not a de Polignac number, because 15781641732401 - 2² = 15781641732397 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 15781641732401.

It is not a weakly prime, because it can be changed into another prime (15781641722401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7890820866200 + 7890820866201.

It is an arithmetic number, because the mean of its divisors is an integer number (7890820866201).

Almost surely, 2^{15781641732401} is an apocalyptic number.

It is an amenable number.

15781641732401 is a deficient number, since it is larger than the sum of its proper divisors (1).

15781641732401 is an equidigital number, since it uses as much as digits as its factorization.

15781641732401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1128960, while the sum is 50.

The spelling of 15781641732401 in words is "fifteen trillion, seven hundred eighty-one billion, six hundred forty-one million, seven hundred thirty-two thousand, four hundred one".