21351452036 has 12 divisors (see below), whose sum is σ = 37432127628. Its totient is φ = 10656558432.

The previous prime is 21351451999. The next prime is 21351452077. The reversal of 21351452036 is 63025415312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2250553600 + 19100898436 = 47440^2 + 138206^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21351451993 and 21351452011.

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, 4789391 + ... + 4793846.

It is an arithmetic number, because the mean of its divisors is an integer number (3119343969).

Almost surely, 2^21351452036 is an apocalyptic number.

It is an amenable number.

21351452036 is a deficient number, since it is larger than the sum of its proper divisors (16080675592).

21351452036 is a wasteful number, since it uses less digits than its factorization.

21351452036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9583798 (or 9583796 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 32.

Adding to 21351452036 its reverse (63025415312), we get a palindrome (84376867348).

The spelling of 21351452036 in words is "twenty-one billion, three hundred fifty-one million, four hundred fifty-two thousand, thirty-six".