16031407661 has 2 divisors, whose sum is σ = 16031407662. Its totient is φ = 16031407660.

The previous prime is 16031407649. The next prime is 16031407697. The reversal of 16031407661 is 16670413061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14812350436 + 1219057225 = 121706^2 + 34915^2 .

It is a cyclic number.

It is not a de Polignac number, because 16031407661 - 2¹⁸ = 16031145517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16031400661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8015703830 + 8015703831.

It is an arithmetic number, because the mean of its divisors is an integer number (8015703831).

Almost surely, 2^16031407661 is an apocalyptic number.

It is an amenable number.

16031407661 is a deficient number, since it is larger than the sum of its proper divisors (1).

16031407661 is an equidigital number, since it uses as much as digits as its factorization.

16031407661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 35.

The spelling of 16031407661 in words is "sixteen billion, thirty-one million, four hundred seven thousand, six hundred sixty-one".