21055521516670 has 16 divisors (see below), whose sum is σ = 37913297941728. Its totient is φ = 8419239892960.

The previous prime is 21055521516661. The next prime is 21055521516703. The reversal of 21055521516670 is 7661512555012.

It is a self number, because there is not a number n which added to its sum of digits gives 21055521516670.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 371059426 + ... + 371116165.

It is an arithmetic number, because the mean of its divisors is an integer number (2369581121358).

Almost surely, 2^{21055521516670} is an apocalyptic number.

21055521516670 is a deficient number, since it is larger than the sum of its proper divisors (16857776425058).

21055521516670 is a wasteful number, since it uses less digits than its factorization.

21055521516670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742178435.

The product of its (nonzero) digits is 630000, while the sum is 46.

The spelling of 21055521516670 in words is "twenty-one trillion, fifty-five billion, five hundred twenty-one million, five hundred sixteen thousand, six hundred seventy".