21121101109951 has 2 divisors, whose sum is σ = 21121101109952. Its totient is φ = 21121101109950.

The previous prime is 21121101109897. The next prime is 21121101110059. The reversal of 21121101109951 is 15990110112112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21121101109951 - 2⁹ = 21121101109439 is a prime.

It is a super-2 number, since 2×21121101109951² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121101109751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560550554975 + 10560550554976.

It is an arithmetic number, because the mean of its divisors is an integer number (10560550554976).

Almost surely, 2^{21121101109951} is an apocalyptic number.

21121101109951 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121101109951 is an equidigital number, since it uses as much as digits as its factorization.

21121101109951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 34.

The spelling of 21121101109951 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred one million, one hundred nine thousand, nine hundred fifty-one".