1891029961 has 2 divisors, whose sum is σ = 1891029962. Its totient is φ = 1891029960.

The previous prime is 1891029949. The next prime is 1891030051. The reversal of 1891029961 is 1699201981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1857610000 + 33419961 = 43100^2 + 5781^2 .

It is a cyclic number.

It is not a de Polignac number, because 1891029961 - 2¹¹ = 1891027913 is a prime.

It is not a weakly prime, because it can be changed into another prime (1891029461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945514980 + 945514981.

It is an arithmetic number, because the mean of its divisors is an integer number (945514981).

Almost surely, 2^1891029961 is an apocalyptic number.

It is an amenable number.

1891029961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891029961 is an equidigital number, since it uses as much as digits as its factorization.

1891029961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 46.

The square root of 1891029961 is about 43485.9743020666. The cubic root of 1891029961 is about 1236.6101397995.

The spelling of 1891029961 in words is "one billion, eight hundred ninety-one million, twenty-nine thousand, nine hundred sixty-one".