21054345514515 has 24 divisors (see below), whose sum is σ = 36498236119488. Its totient is φ = 11227742050560.

The previous prime is 21054345514513. The next prime is 21054345514519. The reversal of 21054345514515 is 51541554345012.

21054345514515 is a `hidden beast` number, since 2 + 1 + 0 + 5 + 43 + 4 + 551 + 4 + 51 + 5 = 666.

It is not a de Polignac number, because 21054345514515 - 2¹ = 21054345514513 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (21054345514513) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25468299 + ... + 26281988.

It is an arithmetic number, because the mean of its divisors is an integer number (1520759838312).

Almost surely, 2^{21054345514515} is an apocalyptic number.

21054345514515 is a deficient number, since it is larger than the sum of its proper divisors (15443890604973).

21054345514515 is a wasteful number, since it uses less digits than its factorization.

21054345514515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51759339 (or 51759336 counting only the distinct ones).

The product of its (nonzero) digits is 1200000, while the sum is 45.

Adding to 21054345514515 its reverse (51541554345012), we get a palindrome (72595899859527).

The spelling of 21054345514515 in words is "twenty-one trillion, fifty-four billion, three hundred forty-five million, five hundred fourteen thousand, five hundred fifteen".