1961907749 has 2 divisors, whose sum is σ = 1961907750. Its totient is φ = 1961907748.

The previous prime is 1961907743. The next prime is 1961907799. The reversal of 1961907749 is 9477091691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1934680225 + 27227524 = 43985^2 + 5218^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961907749 - 2⁴ = 1961907733 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1961907749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1961907743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980953874 + 980953875.

It is an arithmetic number, because the mean of its divisors is an integer number (980953875).

Almost surely, 2^1961907749 is an apocalyptic number.

It is an amenable number.

1961907749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961907749 is an equidigital number, since it uses as much as digits as its factorization.

1961907749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 857304, while the sum is 53.

The square root of 1961907749 is about 44293.4278307742. The cubic root of 1961907749 is about 1251.8708516543.

The spelling of 1961907749 in words is "one billion, nine hundred sixty-one million, nine hundred seven thousand, seven hundred forty-nine".