21254001320 has 16 divisors (see below), whose sum is σ = 47821503060. Its totient is φ = 8501600512.

The previous prime is 21254001277. The next prime is 21254001337. The reversal of 21254001320 is 2310045212.

It can be written as a sum of positive squares in 2 ways, for example, as 20175929764 + 1078071556 = 142042^2 + 32834^2 .

It is a super-2 number, since 2×21254001320² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21254001292 and 21254001301.

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 3 ways as a sum of consecutive naturals, for example, 265674977 + ... + 265675056.

Almost surely, 2^21254001320 is an apocalyptic number.

21254001320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21254001320 is an abundant number, since it is smaller than the sum of its proper divisors (26567501740).

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

21254001320 is a wasteful number, since it uses less digits than its factorization.

21254001320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531350044 (or 531350040 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 21254001320 its reverse (2310045212), we get a palindrome (23564046532).

The spelling of 21254001320 in words is "twenty-one billion, two hundred fifty-four million, one thousand, three hundred twenty".