21515454101345 has 16 divisors (see below), whose sum is σ = 26724020901888. Its totient is φ = 16611738448320.

The previous prime is 21515454101341. The next prime is 21515454101359. The reversal of 21515454101345 is 54310145451512.

It is not a de Polignac number, because 21515454101345 - 2² = 21515454101341 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21515454101341) 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, 189056714 + ... + 189170483.

It is an arithmetic number, because the mean of its divisors is an integer number (1670251306368).

Almost surely, 2^{21515454101345} is an apocalyptic number.

It is an amenable number.

21515454101345 is a deficient number, since it is larger than the sum of its proper divisors (5208566800543).

21515454101345 is a wasteful number, since it uses less digits than its factorization.

21515454101345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378227600.

The product of its (nonzero) digits is 240000, while the sum is 41.

Adding to 21515454101345 its reverse (54310145451512), we get a palindrome (75825599552857).

The spelling of 21515454101345 in words is "twenty-one trillion, five hundred fifteen billion, four hundred fifty-four million, one hundred one thousand, three hundred forty-five".