21542305351 has 4 divisors (see below), whose sum is σ = 24619777552. Its totient is φ = 18464833152.

The previous prime is 21542305339. The next prime is 21542305363. The reversal of 21542305351 is 15350324512.

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

It is an interprime number because it is at equal distance from previous prime (21542305339) and next prime (21542305363).

It is a cyclic number.

It is not a de Polignac number, because 21542305351 - 2¹³ = 21542297159 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 (21542305331) 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, 1538736090 + ... + 1538736103.

It is an arithmetic number, because the mean of its divisors is an integer number (6154944388).

Almost surely, 2^21542305351 is an apocalyptic number.

21542305351 is a deficient number, since it is larger than the sum of its proper divisors (3077472201).

21542305351 is an equidigital number, since it uses as much as digits as its factorization.

21542305351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3077472200.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 21542305351 its reverse (15350324512), we get a palindrome (36892629863).

The spelling of 21542305351 in words is "twenty-one billion, five hundred forty-two million, three hundred five thousand, three hundred fifty-one".