21001221310 has 32 divisors (see below), whose sum is σ = 38893478400. Its totient is φ = 8159773440.

The previous prime is 21001221259. The next prime is 21001221383. The reversal of 21001221310 is 1312210012.

It is a super-2 number, since 2×21001221310² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 17950 + ... + 205729.

It is an arithmetic number, because the mean of its divisors is an integer number (1215421200).

Almost surely, 2^21001221310 is an apocalyptic number.

21001221310 is a deficient number, since it is larger than the sum of its proper divisors (17892257090).

21001221310 is a wasteful number, since it uses less digits than its factorization.

21001221310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223956.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21001221310 its reverse (1312210012), we get a palindrome (22313431322).

The spelling of 21001221310 in words is "twenty-one billion, one million, two hundred twenty-one thousand, three hundred ten".