21421011111500 has 192 divisors, whose sum is σ = 62814195505152. Its totient is φ = 6163087968000.

The previous prime is 21421011111481. The next prime is 21421011111503. The reversal of 21421011111500 is 511111012412.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (21421011111503) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20899112 + ... + 21900111.

It is an arithmetic number, because the mean of its divisors is an integer number (327157268256).

Almost surely, 2^{21421011111500} is an apocalyptic number.

21421011111500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21421011111500 is an abundant number, since it is smaller than the sum of its proper divisors (41393184393652).

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

21421011111500 is a wasteful number, since it uses less digits than its factorization.

21421011111500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42799273 (or 42799261 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 20.

Adding to 21421011111500 its reverse (511111012412), we get a palindrome (21932122123912).

The spelling of 21421011111500 in words is "twenty-one trillion, four hundred twenty-one billion, eleven million, one hundred eleven thousand, five hundred".