21049973540878 has 8 divisors (see below), whose sum is σ = 32663752046280. Its totient is φ = 10162056192120.

The previous prime is 21049973540831. The next prime is 21049973540879. The reversal of 21049973540878 is 87804537994012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21049973540879) 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, 181465289088 + ... + 181465289203.

It is an arithmetic number, because the mean of its divisors is an integer number (4082969005785).

Almost surely, 2^{21049973540878} is an apocalyptic number.

21049973540878 is a deficient number, since it is larger than the sum of its proper divisors (11613778505402).

21049973540878 is a wasteful number, since it uses less digits than its factorization.

21049973540878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362930578322.

The product of its (nonzero) digits is 121927680, while the sum is 67.

The spelling of 21049973540878 in words is "twenty-one trillion, forty-nine billion, nine hundred seventy-three million, five hundred forty thousand, eight hundred seventy-eight".