21551210067 has 8 divisors (see below), whose sum is σ = 28740626896. Its totient is φ = 14364633312.

The previous prime is 21551210041. The next prime is 21551210071. The reversal of 21551210067 is 76001215512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21551210067 - 2¹² = 21551205971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21551214067) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 692248 + ... + 722709.

It is an arithmetic number, because the mean of its divisors is an integer number (3592578362).

Almost surely, 2^21551210067 is an apocalyptic number.

21551210067 is a deficient number, since it is larger than the sum of its proper divisors (7189416829).

21551210067 is a wasteful number, since it uses less digits than its factorization.

21551210067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1420037.

The product of its (nonzero) digits is 4200, while the sum is 30.

Adding to 21551210067 its reverse (76001215512), we get a palindrome (97552425579).

Subtracting 21551210067 from its reverse (76001215512), we obtain a palindrome (54450005445).

The spelling of 21551210067 in words is "twenty-one billion, five hundred fifty-one million, two hundred ten thousand, sixty-seven".