21121012000 has 96 divisors (see below), whose sum is σ = 56612110464. Its totient is φ = 7680352000.

The previous prime is 21121011959. The next prime is 21121012021. The reversal of 21121012000 is 21012112.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196012 + ... + 284011.

It is an arithmetic number, because the mean of its divisors is an integer number (589709484).

Almost surely, 2^21121012000 is an apocalyptic number.

21121012000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121012000 is an abundant number, since it is smaller than the sum of its proper divisors (35491098464).

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

21121012000 is a wasteful number, since it uses less digits than its factorization.

21121012000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480059 (or 480041 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21121012000 its reverse (21012112), we get a palindrome (21142024112).

The spelling of 21121012000 in words is "twenty-one billion, one hundred twenty-one million, twelve thousand".