21725311331345 has 4 divisors (see below), whose sum is σ = 26070373597620. Its totient is φ = 17380249065072.

The previous prime is 21725311331303. The next prime is 21725311331359. The reversal of 21725311331345 is 54313311352712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16571217242176 + 5154094089169 = 4070776^2 + 2270263^2 .

It is a cyclic number.

It is not a de Polignac number, because 21725311331345 - 2⁸ = 21725311331089 is a prime.

It is a super-3 number, since 3×21725311331345³ (a number of 41 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2172531133130 + ... + 2172531133139.

It is an arithmetic number, because the mean of its divisors is an integer number (6517593399405).

Almost surely, 2^{21725311331345} is an apocalyptic number.

It is an amenable number.

21725311331345 is a deficient number, since it is larger than the sum of its proper divisors (4345062266275).

21725311331345 is an equidigital number, since it uses as much as digits as its factorization.

21725311331345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4345062266274.

The product of its digits is 226800, while the sum is 41.

The spelling of 21725311331345 in words is "twenty-one trillion, seven hundred twenty-five billion, three hundred eleven million, three hundred thirty-one thousand, three hundred forty-five".