21042501145 has 8 divisors (see below), whose sum is σ = 26736354504. Its totient is φ = 15843765504.

The previous prime is 21042501131. The next prime is 21042501149. The reversal of 21042501145 is 54110524012.

It can be written as a sum of positive squares in 4 ways, for example, as 12118487056 + 8924014089 = 110084^2 + 94467^2 .

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 21042501145 - 2⁷ = 21042501017 is a prime.

It is a super-2 number, since 2×21042501145² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21042501149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123779334 + ... + 123779503.

It is an arithmetic number, because the mean of its divisors is an integer number (3342044313).

Almost surely, 2^21042501145 is an apocalyptic number.

It is an amenable number.

21042501145 is a deficient number, since it is larger than the sum of its proper divisors (5693853359).

21042501145 is a wasteful number, since it uses less digits than its factorization.

21042501145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247558859.

The product of its (nonzero) digits is 1600, while the sum is 25.

The spelling of 21042501145 in words is "twenty-one billion, forty-two million, five hundred one thousand, one hundred forty-five".