21257034 has 8 divisors (see below), whose sum is σ = 42514080. Its totient is φ = 7085676.

The previous prime is 21257017. The next prime is 21257053. The reversal of 21257034 is 43075212.

It is a sphenic number, since it is the product of 3 distinct primes.

21257034 is an admirable number.

It is a super-2 number, since 2×21257034² = 903722988954312, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21256995 and 21257013.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1771414 + ... + 1771425.

It is an arithmetic number, because the mean of its divisors is an integer number (5314260).

Almost surely, 2^21257034 is an apocalyptic number.

21257034 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21257034 is a wasteful number, since it uses less digits than its factorization.

21257034 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3542844.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 21257034 is about 4610.5351099411. The cubic root of 21257034 is about 277.0134710005.

The spelling of 21257034 in words is "twenty-one million, two hundred fifty-seven thousand, thirty-four".