61171645021 has 2 divisors, whose sum is σ = 61171645022. Its totient is φ = 61171645020.

The previous prime is 61171644991. The next prime is 61171645027. The reversal of 61171645021 is 12054617116.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60718380921 + 453264100 = 246411^2 + 21290^2 .

It is a cyclic number.

It is not a de Polignac number, because 61171645021 - 2¹³ = 61171636829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61171645027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30585822510 + 30585822511.

It is an arithmetic number, because the mean of its divisors is an integer number (30585822511).

Almost surely, 2^61171645021 is an apocalyptic number.

It is an amenable number.

61171645021 is a deficient number, since it is larger than the sum of its proper divisors (1).

61171645021 is an equidigital number, since it uses as much as digits as its factorization.

61171645021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 34.

The spelling of 61171645021 in words is "sixty-one billion, one hundred seventy-one million, six hundred forty-five thousand, twenty-one".