21201031502 has 64 divisors (see below), whose sum is σ = 38238621696. Its totient is φ = 8625070080.

The previous prime is 21201031499. The next prime is 21201031507. The reversal of 21201031502 is 20513010212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201031507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7471628 + ... + 7474464.

It is an arithmetic number, because the mean of its divisors is an integer number (597478464).

Almost surely, 2^21201031502 is an apocalyptic number.

21201031502 is a deficient number, since it is larger than the sum of its proper divisors (17037590194).

21201031502 is a wasteful number, since it uses less digits than its factorization.

21201031502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3201.

The product of its (nonzero) digits is 120, while the sum is 17.

Adding to 21201031502 its reverse (20513010212), we get a palindrome (41714041714).

The spelling of 21201031502 in words is "twenty-one billion, two hundred one million, thirty-one thousand, five hundred two".