21505310551124 has 6 divisors (see below), whose sum is σ = 37634293464474. Its totient is φ = 10752655275560.

The previous prime is 21505310551097. The next prime is 21505310551141. The reversal of 21505310551124 is 42115501350512.

It can be written as a sum of positive squares in only one way, i.e., 11198526816400 + 10306783734724 = 3346420^2 + 3210418^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2688163818887 + ... + 2688163818894.

It is an arithmetic number, because the mean of its divisors is an integer number (6272382244079).

Almost surely, 2^{21505310551124} is an apocalyptic number.

It is an amenable number.

21505310551124 is a deficient number, since it is larger than the sum of its proper divisors (16128982913350).

21505310551124 is a wasteful number, since it uses less digits than its factorization.

21505310551124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5376327637785 (or 5376327637783 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 35.

The spelling of 21505310551124 in words is "twenty-one trillion, five hundred five billion, three hundred ten million, five hundred fifty-one thousand, one hundred twenty-four".