21011431505104 has 20 divisors (see below), whose sum is σ = 40733469336420. Its totient is φ = 10499568450560.

The previous prime is 21011431505059. The next prime is 21011431505107. The reversal of 21011431505104 is 40150513411012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10403721230400 + 10607710274704 = 3225480^2 + 3256948^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011431505107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 384178177 + ... + 384232864.

It is an arithmetic number, because the mean of its divisors is an integer number (2036673466821).

Almost surely, 2^{21011431505104} is an apocalyptic number.

It is an amenable number.

21011431505104 is a deficient number, since it is larger than the sum of its proper divisors (19722037831316).

21011431505104 is a wasteful number, since it uses less digits than its factorization.

21011431505104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768412758 (or 768412752 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 28.

Adding to 21011431505104 its reverse (40150513411012), we get a palindrome (61161944916116).

The spelling of 21011431505104 in words is "twenty-one trillion, eleven billion, four hundred thirty-one million, five hundred five thousand, one hundred four".