21540425045 has 8 divisors (see below), whose sum is σ = 25878676824. Its totient is φ = 17212228864.

The previous prime is 21540425017. The next prime is 21540425063. The reversal of 21540425045 is 54052404512.

It can be written as a sum of positive squares in 4 ways, for example, as 11459060209 + 10081364836 = 107047^2 + 100406^2 .

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 21540425045 - 2¹⁸ = 21540162901 is a prime.

It is a super-2 number, since 2×21540425045² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 2509184 + ... + 2517753.

It is an arithmetic number, because the mean of its divisors is an integer number (3234834603).

Almost surely, 2^21540425045 is an apocalyptic number.

It is an amenable number.

21540425045 is a deficient number, since it is larger than the sum of its proper divisors (4338251779).

21540425045 is an equidigital number, since it uses as much as digits as its factorization.

21540425045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5027799.

The product of its (nonzero) digits is 32000, while the sum is 32.

Adding to 21540425045 its reverse (54052404512), we get a palindrome (75592829557).

The spelling of 21540425045 in words is "twenty-one billion, five hundred forty million, four hundred twenty-five thousand, forty-five".