21012475 has 24 divisors (see below), whose sum is σ = 28725840. Its totient is φ = 15120000.

The previous prime is 21012457. The next prime is 21012503. The reversal of 21012475 is 57421012.

It is a happy number.

It is not a de Polignac number, because 21012475 - 2¹¹ = 21010427 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29625 + ... + 30325.

It is an arithmetic number, because the mean of its divisors is an integer number (1196910).

Almost surely, 2^21012475 is an apocalyptic number.

21012475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21012475 is a deficient number, since it is larger than the sum of its proper divisors (7713365).

21012475 is a wasteful number, since it uses less digits than its factorization.

21012475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831 (or 826 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21012475 is about 4583.9366269616. The cubic root of 21012475 is about 275.9470379018.

Adding to 21012475 its reverse (57421012), we get a palindrome (78433487).

The spelling of 21012475 in words is "twenty-one million, twelve thousand, four hundred seventy-five".