21451121444052 has 72 divisors (see below), whose sum is σ = 54519531917760. Its totient is φ = 7111379082240.

The previous prime is 21451121444023. The next prime is 21451121444057. The reversal of 21451121444052 is 25044412115412.

It is a happy number.

21451121444052 is a `hidden beast` number, since 2 + 1 + 45 + 1 + 121 + 4 + 440 + 52 = 666.

It is a super-2 number, since 2×21451121444052² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21451121443998 and 21451121444016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451121444057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25085599 + ... + 25926617.

It is an arithmetic number, because the mean of its divisors is an integer number (757215721080).

Almost surely, 2^{21451121444052} is an apocalyptic number.

It is an amenable number.

21451121444052 is an abundant number, since it is smaller than the sum of its proper divisors (33068410473708).

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

21451121444052 is a wasteful number, since it uses less digits than its factorization.

21451121444052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844893 (or 844888 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 36.

Adding to 21451121444052 its reverse (25044412115412), we get a palindrome (46495533559464).

The spelling of 21451121444052 in words is "twenty-one trillion, four hundred fifty-one billion, one hundred twenty-one million, four hundred forty-four thousand, fifty-two".