1691021992 has 64 divisors (see below), whose sum is σ = 3551558400. Its totient is φ = 748320000.

The previous prime is 1691021957. The next prime is 1691022001. The reversal of 1691021992 is 2991201961.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 540609 + ... + 543727.

It is an arithmetic number, because the mean of its divisors is an integer number (55493100).

Almost surely, 2^1691021992 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1691021992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1775779200).

1691021992 is an abundant number, since it is smaller than the sum of its proper divisors (1860536408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1691021992 is a wasteful number, since it uses less digits than its factorization.

1691021992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3298 (or 3294 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 1691021992 is about 41122.0377899734. The cubic root of 1691021992 is about 1191.3784821270.

The spelling of 1691021992 in words is "one billion, six hundred ninety-one million, twenty-one thousand, nine hundred ninety-two".