1691331961 has 16 divisors (see below), whose sum is σ = 1877743296. Its totient is φ = 1510600000.

The previous prime is 1691331953. The next prime is 1691331991.

1691331961 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 1691331961 - 2³ = 1691331953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1691331991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139731 + ... + 151351.

It is an arithmetic number, because the mean of its divisors is an integer number (117358956).

Almost surely, 2^1691331961 is an apocalyptic number.

1691331961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1691331961 is a deficient number, since it is larger than the sum of its proper divisors (186411335).

1691331961 is a wasteful number, since it uses less digits than its factorization.

1691331961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11864.

The product of its digits is 26244, while the sum is 40.

The square root of 1691331961 is about 41125.8065088090. The cubic root of 1691331961 is about 1191.4512720014.

The spelling of 1691331961 in words is "one billion, six hundred ninety-one million, three hundred thirty-one thousand, nine hundred sixty-one".