21152345623605 has 24 divisors (see below), whose sum is σ = 41901789426432. Its totient is φ = 9669643713504.

The previous prime is 21152345623553. The next prime is 21152345623627. The reversal of 21152345623605 is 50632654325112.

21152345623605 is a `hidden beast` number, since 2 + 1 + 1 + 5 + 2 + 34 + 5 + 6 + 2 + 3 + 605 = 666.

It is not a de Polignac number, because 21152345623605 - 2¹⁰ = 21152345622581 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33575151469 + ... + 33575152098.

It is an arithmetic number, because the mean of its divisors is an integer number (1745907892768).

Almost surely, 2^{21152345623605} is an apocalyptic number.

It is an amenable number.

21152345623605 is a deficient number, since it is larger than the sum of its proper divisors (20749443802827).

21152345623605 is a wasteful number, since it uses less digits than its factorization.

21152345623605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67150303585 (or 67150303582 counting only the distinct ones).

The product of its (nonzero) digits is 1296000, while the sum is 45.

Adding to 21152345623605 its reverse (50632654325112), we get a palindrome (71784999948717).

The spelling of 21152345623605 in words is "twenty-one trillion, one hundred fifty-two billion, three hundred forty-five million, six hundred twenty-three thousand, six hundred five".