20415521231263 has 16 divisors (see below), whose sum is σ = 21614998735872. Its totient is φ = 19242331416000.

The previous prime is 20415521231167. The next prime is 20415521231269. The reversal of 20415521231263 is 36213212551402.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20415521231263 - 2⁹ = 20415521230751 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 (20415521231269) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 423918 + ... + 6403963.

It is an arithmetic number, because the mean of its divisors is an integer number (1350937420992).

Almost surely, 2^{20415521231263} is an apocalyptic number.

20415521231263 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20415521231263 is a deficient number, since it is larger than the sum of its proper divisors (1199477504609).

20415521231263 is a wasteful number, since it uses less digits than its factorization.

20415521231263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6829806.

The product of its (nonzero) digits is 86400, while the sum is 37.

Adding to 20415521231263 its reverse (36213212551402), we get a palindrome (56628733782665).

The spelling of 20415521231263 in words is "twenty trillion, four hundred fifteen billion, five hundred twenty-one million, two hundred thirty-one thousand, two hundred sixty-three".