140805661 has 2 divisors, whose sum is σ = 140805662. Its totient is φ = 140805660.

The previous prime is 140805653. The next prime is 140805667. The reversal of 140805661 is 166508041.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140422500 + 383161 = 11850^2 + 619^2 .

It is a cyclic number.

It is not a de Polignac number, because 140805661 - 2³ = 140805653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (140805667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70402830 + 70402831.

It is an arithmetic number, because the mean of its divisors is an integer number (70402831).

Almost surely, 2^140805661 is an apocalyptic number.

It is an amenable number.

140805661 is a deficient number, since it is larger than the sum of its proper divisors (1).

140805661 is an equidigital number, since it uses as much as digits as its factorization.

140805661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 140805661 is about 11866.1561172943. The cubic root of 140805661 is about 520.2435508518.

The spelling of 140805661 in words is "one hundred forty million, eight hundred five thousand, six hundred sixty-one".