21261012546351 has 4 divisors (see below), whose sum is σ = 28348016728472. Its totient is φ = 14174008364232.

The previous prime is 21261012546341. The next prime is 21261012546359. The reversal of 21261012546351 is 15364521016212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21261012546351 - 2²¹ = 21261010449199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21261012546359) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3543502091056 + ... + 3543502091061.

It is an arithmetic number, because the mean of its divisors is an integer number (7087004182118).

Almost surely, 2^{21261012546351} is an apocalyptic number.

21261012546351 is a deficient number, since it is larger than the sum of its proper divisors (7087004182121).

21261012546351 is an equidigital number, since it uses as much as digits as its factorization.

21261012546351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7087004182120.

The product of its (nonzero) digits is 86400, while the sum is 39.

The spelling of 21261012546351 in words is "twenty-one trillion, two hundred sixty-one billion, twelve million, five hundred forty-six thousand, three hundred fifty-one".