21365535401 has 8 divisors (see below), whose sum is σ = 24418893120. Its totient is φ = 18312462288.

The previous prime is 21365535307. The next prime is 21365535409. The reversal of 21365535401 is 10453556312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21365535401 is a prime.

It is a super-2 number, since 2×21365535401² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21365535409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126230 + ... + 242208.

It is an arithmetic number, because the mean of its divisors is an integer number (3052361640).

Almost surely, 2^21365535401 is an apocalyptic number.

It is an amenable number.

21365535401 is a deficient number, since it is larger than the sum of its proper divisors (3053357719).

21365535401 is a wasteful number, since it uses less digits than its factorization.

21365535401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142303.

The product of its (nonzero) digits is 54000, while the sum is 35.

The spelling of 21365535401 in words is "twenty-one billion, three hundred sixty-five million, five hundred thirty-five thousand, four hundred one".