164256021 has 24 divisors (see below), whose sum is σ = 240724224. Its totient is φ = 107916480.

The previous prime is 164256019. The next prime is 164256031. The reversal of 164256021 is 120652461.

164256021 is a `hidden beast` number, since 16 + 42 + 5 + 602 + 1 = 666.

It is not a de Polignac number, because 164256021 - 2¹ = 164256019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164256031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 270300 + ... + 270906.

It is an arithmetic number, because the mean of its divisors is an integer number (10030176).

Almost surely, 2^164256021 is an apocalyptic number.

It is an amenable number.

164256021 is a deficient number, since it is larger than the sum of its proper divisors (76468203).

164256021 is a wasteful number, since it uses less digits than its factorization.

164256021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001 (or 998 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 164256021 is about 12816.2405174060. The cubic root of 164256021 is about 547.6550533509.

The spelling of 164256021 in words is "one hundred sixty-four million, two hundred fifty-six thousand, twenty-one".