21351251270643 has 32 divisors (see below), whose sum is σ = 32608955136000. Its totient is φ = 12173075988480.

The previous prime is 21351251270641. The next prime is 21351251270711. The reversal of 21351251270643 is 34607215215312.

It is not a de Polignac number, because 21351251270643 - 2¹ = 21351251270641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21351251270595 and 21351251270604.

It is not an unprimeable number, because it can be changed into a prime (21351251270641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135056358 + ... + 135214356.

It is an arithmetic number, because the mean of its divisors is an integer number (1019029848000).

Almost surely, 2^{21351251270643} is an apocalyptic number.

21351251270643 is a deficient number, since it is larger than the sum of its proper divisors (11257703865357).

21351251270643 is a wasteful number, since it uses less digits than its factorization.

21351251270643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172547.

The product of its (nonzero) digits is 302400, while the sum is 42.

Adding to 21351251270643 its reverse (34607215215312), we get a palindrome (55958466485955).

The spelling of 21351251270643 in words is "twenty-one trillion, three hundred fifty-one billion, two hundred fifty-one million, two hundred seventy thousand, six hundred forty-three".