21121541012 has 48 divisors (see below), whose sum is σ = 43448496000. Its totient is φ = 8857330560.

The previous prime is 21121540981. The next prime is 21121541071. The reversal of 21121541012 is 21014512112.

It is a super-2 number, since 2×21121541012² (a number of 21 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 15 ways as a sum of consecutive naturals, for example, 1151489 + ... + 1169687.

It is an arithmetic number, because the mean of its divisors is an integer number (905177000).

Almost surely, 2^21121541012 is an apocalyptic number.

21121541012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21121541012 is an abundant number, since it is smaller than the sum of its proper divisors (22326954988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21121541012 is a wasteful number, since it uses less digits than its factorization.

21121541012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20256 (or 20254 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 20.

The spelling of 21121541012 in words is "twenty-one billion, one hundred twenty-one million, five hundred forty-one thousand, twelve".