21620505111351 has 8 divisors (see below), whose sum is σ = 28827362458224. Its totient is φ = 14413658919360.

The previous prime is 21620505111341. The next prime is 21620505111421. The reversal of 21620505111351 is 15311150502612.

It is a happy number.

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

It is not a de Polignac number, because 21620505111351 - 2¹⁵ = 21620505078583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620505111311) 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, 4329081 + ... + 7872861.

It is an arithmetic number, because the mean of its divisors is an integer number (3603420307278).

Almost surely, 2^{21620505111351} is an apocalyptic number.

21620505111351 is a deficient number, since it is larger than the sum of its proper divisors (7206857346873).

21620505111351 is a wasteful number, since it uses less digits than its factorization.

21620505111351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5577441.

The product of its (nonzero) digits is 9000, while the sum is 33.

Adding to 21620505111351 its reverse (15311150502612), we get a palindrome (36931655613963).

The spelling of 21620505111351 in words is "twenty-one trillion, six hundred twenty billion, five hundred five million, one hundred eleven thousand, three hundred fifty-one".