21051070 has 16 divisors (see below), whose sum is σ = 38607840. Its totient is φ = 8261344.

The previous prime is 21051059. The next prime is 21051091. The reversal of 21051070 is 7015012.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 19330 + ... + 20389.

It is an arithmetic number, because the mean of its divisors is an integer number (2412990).

Almost surely, 2^21051070 is an apocalyptic number.

21051070 is a deficient number, since it is larger than the sum of its proper divisors (17556770).

21051070 is a wasteful number, since it uses less digits than its factorization.

21051070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39779.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 21051070 is about 4588.1445051349. The cubic root of 21051070 is about 276.1158846138.

Adding to 21051070 its reverse (7015012), we get a palindrome (28066082).

The spelling of 21051070 in words is "twenty-one million, fifty-one thousand, seventy".