21121455052 has 12 divisors (see below), whose sum is σ = 37024052296. Its totient is φ = 10543154400.

The previous prime is 21121455041. The next prime is 21121455101. The reversal of 21121455052 is 25055412112.

It is a super-2 number, since 2×21121455052² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121455052.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4390578 + ... + 4395385.

Almost surely, 2^21121455052 is an apocalyptic number.

It is an amenable number.

21121455052 is a deficient number, since it is larger than the sum of its proper divisors (15902597244).

21121455052 is a wasteful number, since it uses less digits than its factorization.

21121455052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8786568 (or 8786566 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 28.

Adding to 21121455052 its reverse (25055412112), we get a palindrome (46176867164).

The spelling of 21121455052 in words is "twenty-one billion, one hundred twenty-one million, four hundred fifty-five thousand, fifty-two".