1991742733 has 8 divisors (see below), whose sum is σ = 2008233216. Its totient is φ = 1975272000.

The previous prime is 1991742691. The next prime is 1991742761. The reversal of 1991742733 is 3372471991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1991742733 - 2²⁵ = 1958188301 is a prime.

It is a super-2 number, since 2×1991742733² = 7934078228916618578, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991712733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 251685 + ... + 259477.

It is an arithmetic number, because the mean of its divisors is an integer number (251029152).

Almost surely, 2^1991742733 is an apocalyptic number.

It is an amenable number.

1991742733 is a deficient number, since it is larger than the sum of its proper divisors (16490483).

1991742733 is a wasteful number, since it uses less digits than its factorization.

1991742733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9875.

The product of its digits is 285768, while the sum is 46.

The square root of 1991742733 is about 44628.9450132983. The cubic root of 1991742733 is about 1258.1847407520.

The spelling of 1991742733 in words is "one billion, nine hundred ninety-one million, seven hundred forty-two thousand, seven hundred thirty-three".