921791740 has 24 divisors (see below), whose sum is σ = 1967499072. Its totient is φ = 362671680.

The previous prime is 921791711. The next prime is 921791743. The reversal of 921791740 is 47197129.

It is a junction number, because it is equal to n+sod(n) for n = 921791693 and 921791702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921791743) 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 7 ways as a sum of consecutive naturals, for example, 376564 + ... + 379003.

It is an arithmetic number, because the mean of its divisors is an integer number (81979128).

Almost surely, 2^921791740 is an apocalyptic number.

It is an amenable number.

921791740 is an abundant number, since it is smaller than the sum of its proper divisors (1045707332).

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

921791740 is a wasteful number, since it uses less digits than its factorization.

921791740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 755637 (or 755635 counting only the distinct ones).

The product of its (nonzero) digits is 31752, while the sum is 40.

The square root of 921791740 is about 30361.0233687865. The cubic root of 921791740 is about 973.2198031195.

The spelling of 921791740 in words is "nine hundred twenty-one million, seven hundred ninety-one thousand, seven hundred forty".