21115653465206 has 4 divisors (see below), whose sum is σ = 31673480197812. Its totient is φ = 10557826732602.

The previous prime is 21115653465139. The next prime is 21115653465227. The reversal of 21115653465206 is 60256435651112.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5278913366300 + ... + 5278913366303.

It is an arithmetic number, because the mean of its divisors is an integer number (7918370049453).

Almost surely, 2^{21115653465206} is an apocalyptic number.

21115653465206 is a deficient number, since it is larger than the sum of its proper divisors (10557826732606).

21115653465206 is a wasteful number, since it uses less digits than its factorization.

21115653465206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10557826732605.

The product of its (nonzero) digits is 1296000, while the sum is 47.

The spelling of 21115653465206 in words is "twenty-one trillion, one hundred fifteen billion, six hundred fifty-three million, four hundred sixty-five thousand, two hundred six".