21403161312552 has 48 divisors (see below), whose sum is σ = 58618208668500. Its totient is φ = 7054225449216.

The previous prime is 21403161312551. The next prime is 21403161312571. The reversal of 21403161312552 is 25521316130412.

21403161312552 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 31 + 61 + 3 + 12 + 552 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21387165639876 + 15995672676 = 4624626^2 + 126474^2 .

It is a super-2 number, since 2×21403161312552² (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 not an unprimeable number, because it can be changed into a prime (21403161312551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1670028027 + ... + 1670040842.

Almost surely, 2^{21403161312552} is an apocalyptic number.

It is an amenable number.

21403161312552 is an abundant number, since it is smaller than the sum of its proper divisors (37215047355948).

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

21403161312552 is a wasteful number, since it uses less digits than its factorization.

21403161312552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3340068970 (or 3340068963 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

Adding to 21403161312552 its reverse (25521316130412), we get a palindrome (46924477442964).

The spelling of 21403161312552 in words is "twenty-one trillion, four hundred three billion, one hundred sixty-one million, three hundred twelve thousand, five hundred fifty-two".