21660196583425 has 12 divisors (see below), whose sum is σ = 26859074530860. Its totient is φ = 17327879352320.

The previous prime is 21660196583387. The next prime is 21660196583429. The reversal of 21660196583425 is 52438569106612.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 2624698088464 + 19035498494961 = 1620092^2 + 4362969^2 .

It is not a de Polignac number, because 21660196583425 - 2³⁵ = 21625836845057 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21660196583425.

It is not an unprimeable number, because it can be changed into a prime (21660196583429) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5350720 + ... + 8482369.

It is an arithmetic number, because the mean of its divisors is an integer number (2238256210905).

Almost surely, 2^{21660196583425} is an apocalyptic number.

21660196583425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21660196583425 is a deficient number, since it is larger than the sum of its proper divisors (5198877947435).

21660196583425 is a wasteful number, since it uses less digits than its factorization.

21660196583425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13895732 (or 13895727 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 58.

The spelling of 21660196583425 in words is "twenty-one trillion, six hundred sixty billion, one hundred ninety-six million, five hundred eighty-three thousand, four hundred twenty-five".