921717641 has 8 divisors (see below), whose sum is σ = 998943624. Its totient is φ = 845395200.

The previous prime is 921717623. The next prime is 921717673. The reversal of 921717641 is 146717129.

921717641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 55651600 + 866066041 = 7460^2 + 29429^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-921717641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 921717595 and 921717604.

It is not an unprimeable number, because it can be changed into a prime (921767641) 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, 223760 + ... + 227841.

It is an arithmetic number, because the mean of its divisors is an integer number (124867953).

Almost surely, 2^921717641 is an apocalyptic number.

It is an amenable number.

921717641 is a deficient number, since it is larger than the sum of its proper divisors (77225983).

921717641 is a wasteful number, since it uses less digits than its factorization.

921717641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451771.

The product of its digits is 21168, while the sum is 38.

The square root of 921717641 is about 30359.8030461332. The cubic root of 921717641 is about 973.1937247247.

The spelling of 921717641 in words is "nine hundred twenty-one million, seven hundred seventeen thousand, six hundred forty-one".