21053016013561 has 8 divisors (see below), whose sum is σ = 24514563121344. Its totient is φ = 17704962253680.

The previous prime is 21053016013541. The next prime is 21053016013583. The reversal of 21053016013561 is 16531061035012.

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

It is a cyclic number.

It is not a de Polignac number, because 21053016013561 - 2³⁷ = 20915577060089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21053016013511) 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, 28373336575 + ... + 28373337316.

It is an arithmetic number, because the mean of its divisors is an integer number (3064320390168).

Almost surely, 2^{21053016013561} is an apocalyptic number.

It is an amenable number.

21053016013561 is a deficient number, since it is larger than the sum of its proper divisors (3461547107783).

21053016013561 is an equidigital number, since it uses as much as digits as its factorization.

21053016013561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56746673951.

The product of its (nonzero) digits is 16200, while the sum is 34.

Adding to 21053016013561 its reverse (16531061035012), we get a palindrome (37584077048573).

The spelling of 21053016013561 in words is "twenty-one trillion, fifty-three billion, sixteen million, thirteen thousand, five hundred sixty-one".