1601867838661 has 2 divisors, whose sum is σ = 1601867838662. Its totient is φ = 1601867838660.

The previous prime is 1601867838617. The next prime is 1601867838677. The reversal of 1601867838661 is 1668387681061.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1535976029025 + 65891809636 = 1239345^2 + 256694^2 .

It is a cyclic number.

It is not a de Polignac number, because 1601867838661 - 2¹⁵ = 1601867805893 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1601867838661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1601867835661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 800933919330 + 800933919331.

It is an arithmetic number, because the mean of its divisors is an integer number (800933919331).

Almost surely, 2^{1601867838661} is an apocalyptic number.

It is an amenable number.

1601867838661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1601867838661 is an equidigital number, since it uses as much as digits as its factorization.

1601867838661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13934592, while the sum is 61.

The spelling of 1601867838661 in words is "one trillion, six hundred one billion, eight hundred sixty-seven million, eight hundred thirty-eight thousand, six hundred sixty-one".