21057067 has 8 divisors (see below), whose sum is σ = 22840272. Its totient is φ = 19334400.

The previous prime is 21057061. The next prime is 21057083. The reversal of 21057067 is 76075012.

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 21057067 - 2⁷ = 21056939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21057061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14409 + ... + 15802.

It is an arithmetic number, because the mean of its divisors is an integer number (2855034).

Almost surely, 2^21057067 is an apocalyptic number.

21057067 is a deficient number, since it is larger than the sum of its proper divisors (1783205).

21057067 is a wasteful number, since it uses less digits than its factorization.

21057067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30269.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 21057067 is about 4588.7979907597. The cubic root of 21057067 is about 276.1421019628.

The spelling of 21057067 in words is "twenty-one million, fifty-seven thousand, sixty-seven".