1601139662021 has 2 divisors, whose sum is σ = 1601139662022. Its totient is φ = 1601139662020.

The previous prime is 1601139661997. The next prime is 1601139662029. The reversal of 1601139662021 is 1202669311061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1574801617921 + 26338044100 = 1254911^2 + 162290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1601139662021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1601139662029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 800569831010 + 800569831011.

It is an arithmetic number, because the mean of its divisors is an integer number (800569831011).

Almost surely, 2^{1601139662021} is an apocalyptic number.

It is an amenable number.

1601139662021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1601139662021 is an equidigital number, since it uses as much as digits as its factorization.

1601139662021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 38.

The spelling of 1601139662021 in words is "one trillion, six hundred one billion, one hundred thirty-nine million, six hundred sixty-two thousand, twenty-one".