21121034440 has 64 divisors (see below), whose sum is σ = 52616381760. Its totient is φ = 7565733120.

The previous prime is 21121034437. The next prime is 21121034471. The reversal of 21121034440 is 4443012112.

It is a happy number.

It is a super-2 number, since 2×21121034440² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

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, 328747 + ... + 387706.

It is an arithmetic number, because the mean of its divisors is an integer number (822130965).

Almost surely, 2^21121034440 is an apocalyptic number.

21121034440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121034440 is an abundant number, since it is smaller than the sum of its proper divisors (31495347320).

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

21121034440 is a wasteful number, since it uses less digits than its factorization.

21121034440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716542 (or 716538 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21121034440 its reverse (4443012112), we get a palindrome (25564046552).

The spelling of 21121034440 in words is "twenty-one billion, one hundred twenty-one million, thirty-four thousand, four hundred forty".