21621302007 has 16 divisors (see below), whose sum is σ = 30110212608. Its totient is φ = 13774479840.

The previous prime is 21621301979. The next prime is 21621302009. The reversal of 21621302007 is 70020312612.

It is not a de Polignac number, because 21621302007 - 2¹⁸ = 21621039863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621302009) 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 15 ways as a sum of consecutive naturals, for example, 74044 + ... + 220737.

It is an arithmetic number, because the mean of its divisors is an integer number (1881888288).

Almost surely, 2^21621302007 is an apocalyptic number.

21621302007 is a deficient number, since it is larger than the sum of its proper divisors (8488910601).

21621302007 is a wasteful number, since it uses less digits than its factorization.

21621302007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295870.

The product of its (nonzero) digits is 1008, while the sum is 24.

Adding to 21621302007 its reverse (70020312612), we get a palindrome (91641614619).

The spelling of 21621302007 in words is "twenty-one billion, six hundred twenty-one million, three hundred two thousand, seven".