21121434445 has 8 divisors (see below), whose sum is σ = 26163325440. Its totient is φ = 16352078160.

The previous prime is 21121434427. The next prime is 21121434449. The reversal of 21121434445 is 54443412112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21121434445 - 2⁹ = 21121433933 is a prime.

It is a super-2 number, since 2×21121434445² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121434449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68133505 + ... + 68133814.

It is an arithmetic number, because the mean of its divisors is an integer number (3270415680).

Almost surely, 2^21121434445 is an apocalyptic number.

It is an amenable number.

21121434445 is a deficient number, since it is larger than the sum of its proper divisors (5041890995).

21121434445 is a wasteful number, since it uses less digits than its factorization.

21121434445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136267355.

The product of its digits is 15360, while the sum is 31.

Adding to 21121434445 its reverse (54443412112), we get a palindrome (75564846557).

The spelling of 21121434445 in words is "twenty-one billion, one hundred twenty-one million, four hundred thirty-four thousand, four hundred forty-five".