1961981963 has 2 divisors, whose sum is σ = 1961981964. Its totient is φ = 1961981962.

The previous prime is 1961981953. The next prime is 1961981977. The reversal of 1961981963 is 3691891691.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1961981963 - 2¹⁶ = 1961916427 is a prime.

It is not a weakly prime, because it can be changed into another prime (1961981953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980990981 + 980990982.

It is an arithmetic number, because the mean of its divisors is an integer number (980990982).

Almost surely, 2^1961981963 is an apocalyptic number.

1961981963 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961981963 is an equidigital number, since it uses as much as digits as its factorization.

1961981963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 629856, while the sum is 53.

The square root of 1961981963 is about 44294.2655769344. The cubic root of 1961981963 is about 1251.8866364896.

The spelling of 1961981963 in words is "one billion, nine hundred sixty-one million, nine hundred eighty-one thousand, nine hundred sixty-three".