21121885510 has 64 divisors (see below), whose sum is σ = 41800872960. Its totient is φ = 7620721920.

The previous prime is 21121885507. The next prime is 21121885513. The reversal of 21121885510 is 1558812112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21121885507) and next prime (21121885513).

It is a super-2 number, since 2×21121885510² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121885513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8069722 + ... + 8072338.

It is an arithmetic number, because the mean of its divisors is an integer number (653138640).

Almost surely, 2^21121885510 is an apocalyptic number.

21121885510 is a deficient number, since it is larger than the sum of its proper divisors (20678987450).

21121885510 is a wasteful number, since it uses less digits than its factorization.

21121885510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3181.

The product of its (nonzero) digits is 6400, while the sum is 34.

The spelling of 21121885510 in words is "twenty-one billion, one hundred twenty-one million, eight hundred eighty-five thousand, five hundred ten".