21620634006155 has 16 divisors (see below), whose sum is σ = 27135607855104. Its totient is φ = 16506098838240.

The previous prime is 21620634006151. The next prime is 21620634006161. The reversal of 21620634006155 is 55160043602612.

It is a happy number.

It is not a de Polignac number, because 21620634006155 - 2² = 21620634006151 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21620634006151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 218054279 + ... + 218153408.

It is an arithmetic number, because the mean of its divisors is an integer number (1695975490944).

Almost surely, 2^{21620634006155} is an apocalyptic number.

21620634006155 is a deficient number, since it is larger than the sum of its proper divisors (5514973848949).

21620634006155 is a wasteful number, since it uses less digits than its factorization.

21620634006155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436208146.

The product of its (nonzero) digits is 259200, while the sum is 41.

Adding to 21620634006155 its reverse (55160043602612), we get a palindrome (76780677608767).

The spelling of 21620634006155 in words is "twenty-one trillion, six hundred twenty billion, six hundred thirty-four million, six thousand, one hundred fifty-five".