21002985870406 has 8 divisors (see below), whose sum is σ = 31504515716520. Its totient is φ = 10501480631568.

The previous prime is 21002985870371. The next prime is 21002985870431. The reversal of 21002985870406 is 60407858920012.

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

It is a super-2 number, since 2×21002985870406² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3844996 + ... + 7535911.

It is an arithmetic number, because the mean of its divisors is an integer number (3938064464565).

Almost surely, 2^{21002985870406} is an apocalyptic number.

21002985870406 is a deficient number, since it is larger than the sum of its proper divisors (10501529846114).

21002985870406 is a wasteful number, since it uses less digits than its factorization.

21002985870406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12303638.

The product of its (nonzero) digits is 1935360, while the sum is 52.

The spelling of 21002985870406 in words is "twenty-one trillion, two billion, nine hundred eighty-five million, eight hundred seventy thousand, four hundred six".