171611400421 has 2 divisors, whose sum is σ = 171611400422. Its totient is φ = 171611400420.

The previous prime is 171611400379. The next prime is 171611400427. The reversal of 171611400421 is 124004116171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148156477921 + 23454922500 = 384911^2 + 153150^2 .

It is a cyclic number.

It is not a de Polignac number, because 171611400421 - 2⁹ = 171611399909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 171611400421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171611400427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85805700210 + 85805700211.

It is an arithmetic number, because the mean of its divisors is an integer number (85805700211).

Almost surely, 2^171611400421 is an apocalyptic number.

It is an amenable number.

171611400421 is a deficient number, since it is larger than the sum of its proper divisors (1).

171611400421 is an equidigital number, since it uses as much as digits as its factorization.

171611400421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 28.

Adding to 171611400421 its reverse (124004116171), we get a palindrome (295615516592).

The spelling of 171611400421 in words is "one hundred seventy-one billion, six hundred eleven million, four hundred thousand, four hundred twenty-one".