21042478867268 has 24 divisors (see below), whose sum is σ = 37519411953240. Its totient is φ = 10322649792000.

The previous prime is 21042478867261. The next prime is 21042478867271. The reversal of 21042478867268 is 86276887424012.

It can be written as a sum of positive squares in 4 ways, for example, as 13146367627264 + 7896111240004 = 3625792^2 + 2810002^2 .

It is not an unprimeable number, because it can be changed into a prime (21042478867261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38266268 + ... + 38812268.

It is an arithmetic number, because the mean of its divisors is an integer number (1563308831385).

Almost surely, 2^{21042478867268} is an apocalyptic number.

It is an amenable number.

21042478867268 is a deficient number, since it is larger than the sum of its proper divisors (16476933085972).

21042478867268 is a wasteful number, since it uses less digits than its factorization.

21042478867268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727847 (or 727845 counting only the distinct ones).

The product of its (nonzero) digits is 115605504, while the sum is 65.

The spelling of 21042478867268 in words is "twenty-one trillion, forty-two billion, four hundred seventy-eight million, eight hundred sixty-seven thousand, two hundred sixty-eight".