675681921 has 24 divisors (see below), whose sum is σ = 1017895424. Its totient is φ = 431412480.

The previous prime is 675681913. The next prime is 675681931. The reversal of 675681921 is 129186576.

675681921 is a `hidden beast` number, since 67 + 568 + 1 + 9 + 21 = 666.

It is not a de Polignac number, because 675681921 - 2³ = 675681913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (675681931) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14580 + ... + 39546.

Almost surely, 2^675681921 is an apocalyptic number.

It is an amenable number.

675681921 is a deficient number, since it is larger than the sum of its proper divisors (342213503).

675681921 is a wasteful number, since it uses less digits than its factorization.

675681921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25101 (or 25098 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 675681921 is about 25993.8823764362. The cubic root of 675681921 is about 877.5006219101.

The spelling of 675681921 in words is "six hundred seventy-five million, six hundred eighty-one thousand, nine hundred twenty-one".