21366545520442 has 4 divisors (see below), whose sum is σ = 32049818280666. Its totient is φ = 10683272760220.

The previous prime is 21366545520409. The next prime is 21366545520451. The reversal of 21366545520442 is 24402554566312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17654946764841 + 3711598755601 = 4201779^2 + 1926551^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5341636380109 + ... + 5341636380112.

Almost surely, 2^{21366545520442} is an apocalyptic number.

21366545520442 is a deficient number, since it is larger than the sum of its proper divisors (10683272760224).

21366545520442 is a wasteful number, since it uses less digits than its factorization.

21366545520442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10683272760223.

The product of its (nonzero) digits is 6912000, while the sum is 49.

The spelling of 21366545520442 in words is "twenty-one trillion, three hundred sixty-six billion, five hundred forty-five million, five hundred twenty thousand, four hundred forty-two".