21050075 has 6 divisors (see below), whose sum is σ = 26102124. Its totient is φ = 16840040.

The previous prime is 21050059. The next prime is 21050101. The reversal of 21050075 is 57005012.

It is not a de Polignac number, because 21050075 - 2⁴ = 21050059 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 420977 + ... + 421026.

It is an arithmetic number, because the mean of its divisors is an integer number (4350354).

Almost surely, 2^21050075 is an apocalyptic number.

21050075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21050075 is a deficient number, since it is larger than the sum of its proper divisors (5052049).

21050075 is an equidigital number, since it uses as much as digits as its factorization.

21050075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 842013 (or 842008 counting only the distinct ones).

The product of its (nonzero) digits is 350, while the sum is 20.

The square root of 21050075 is about 4588.0360722209. The cubic root of 21050075 is about 276.1115342469. Note that the first 3 decimals are identical.

Adding to 21050075 its reverse (57005012), we get a palindrome (78055087).

It can be divided in two parts, 2105007 and 5, that added together give a palindrome (2105012).

The spelling of 21050075 in words is "twenty-one million, fifty thousand, seventy-five".