855509921 has 8 divisors (see below), whose sum is σ = 1035239040. Its totient is φ = 690159168.

The previous prime is 855509891. The next prime is 855509923. The reversal of 855509921 is 129905558.

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 855509921 - 2⁶ = 855509857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (855509923) 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, 3594461 + ... + 3594698.

It is an arithmetic number, because the mean of its divisors is an integer number (129404880).

Almost surely, 2^855509921 is an apocalyptic number.

It is an amenable number.

855509921 is a deficient number, since it is larger than the sum of its proper divisors (179729119).

855509921 is a wasteful number, since it uses less digits than its factorization.

855509921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7189183.

The product of its (nonzero) digits is 162000, while the sum is 44.

The square root of 855509921 is about 29249.1011998660. The cubic root of 855509921 is about 949.3106433876.

The spelling of 855509921 in words is "eight hundred fifty-five million, five hundred nine thousand, nine hundred twenty-one".