21121002215 has 8 divisors (see below), whose sum is σ = 26836097040. Its totient is φ = 15902872192.

The previous prime is 21121002211. The next prime is 21121002233. The reversal of 21121002215 is 51220012112.

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

It is a cyclic number.

It is not a de Polignac number, because 21121002215 - 2² = 21121002211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a junction number, because it is equal to n+sod(n) for n = 21121002193 and 21121002202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121002211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124241105 + ... + 124241274.

It is an arithmetic number, because the mean of its divisors is an integer number (3354512130).

Almost surely, 2^21121002215 is an apocalyptic number.

21121002215 is a deficient number, since it is larger than the sum of its proper divisors (5715094825).

21121002215 is a wasteful number, since it uses less digits than its factorization.

21121002215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248482401.

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 21121002215 its reverse (51220012112), we get a palindrome (72341014327).

The spelling of 21121002215 in words is "twenty-one billion, one hundred twenty-one million, two thousand, two hundred fifteen".