1691000106721 has 16 divisors (see below), whose sum is σ = 1817292452544. Its totient is φ = 1567690527744.

The previous prime is 1691000106713. The next prime is 1691000106811. The reversal of 1691000106721 is 1276010001961.

It is a cyclic number.

It is not a de Polignac number, because 1691000106721 - 2³ = 1691000106713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1691000106701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32826441 + ... + 32877913.

It is an arithmetic number, because the mean of its divisors is an integer number (113580778284).

Almost surely, 2^{1691000106721} is an apocalyptic number.

It is an amenable number.

1691000106721 is a deficient number, since it is larger than the sum of its proper divisors (126292345823).

1691000106721 is a wasteful number, since it uses less digits than its factorization.

1691000106721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80400.

The product of its (nonzero) digits is 4536, while the sum is 34.

The spelling of 1691000106721 in words is "one trillion, six hundred ninety-one billion, one hundred six thousand, seven hundred twenty-one".