918330021 has 128 divisors (see below), whose sum is σ = 1774080000. Its totient is φ = 466373376.

The previous prime is 918329989. The next prime is 918330029. The reversal of 918330021 is 120033819.

It is not a de Polignac number, because 918330021 - 2⁵ = 918329989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918330029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2991150 + ... + 2991456.

It is an arithmetic number, because the mean of its divisors is an integer number (13860000).

Almost surely, 2^918330021 is an apocalyptic number.

It is an amenable number.

918330021 is a deficient number, since it is larger than the sum of its proper divisors (855749979).

918330021 is a wasteful number, since it uses less digits than its factorization.

918330021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 918330021 is about 30303.9604837388. The cubic root of 918330021 is about 971.9999904740. Note that the first 5 decimals are identical.

Adding to 918330021 its sum of digits (27), we get a cube (918330048 = 972³).

It can be divided in two parts, 9183 and 30021, that added together give a square (39204 = 198²).

The spelling of 918330021 in words is "nine hundred eighteen million, three hundred thirty thousand, twenty-one".