21513201 has 16 divisors (see below), whose sum is σ = 29736960. Its totient is φ = 13824720.

The previous prime is 21513197. The next prime is 21513203. The reversal of 21513201 is 10231512.

It is not a de Polignac number, because 21513201 - 2² = 21513197 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21513203) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 9136 + ... + 11246.

It is an arithmetic number, because the mean of its divisors is an integer number (1858560).

Almost surely, 2^21513201 is an apocalyptic number.

It is an amenable number.

21513201 is a deficient number, since it is larger than the sum of its proper divisors (8223759).

21513201 is a wasteful number, since it uses less digits than its factorization.

21513201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2236.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21513201 is about 4638.2325297466. The cubic root of 21513201 is about 278.1217872961.

Adding to 21513201 its reverse (10231512), we get a palindrome (31744713).

The spelling of 21513201 in words is "twenty-one million, five hundred thirteen thousand, two hundred one".