21400576 has 22 divisors (see below), whose sum is σ = 42782300. Its totient is φ = 10699776.

The previous prime is 21400523. The next prime is 21400583. The reversal of 21400576 is 67500412.

It is a self number, because there is not a number n which added to its sum of digits gives 21400576.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9426 + ... + 11473.

It is an arithmetic number, because the mean of its divisors is an integer number (1944650).

Almost surely, 2^21400576 is an apocalyptic number.

It is an amenable number.

21400576 is a deficient number, since it is larger than the sum of its proper divisors (21381724).

21400576 is an equidigital number, since it uses as much as digits as its factorization.

21400576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20919 (or 20901 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21400576 is about 4626.0756586982. The cubic root of 21400576 is about 277.6356007461.

Adding to 21400576 its reverse (67500412), we get a palindrome (88900988).

The spelling of 21400576 in words is "twenty-one million, four hundred thousand, five hundred seventy-six".