21475534639 has 8 divisors (see below), whose sum is σ = 23148482112. Its totient is φ = 19805584800.

The previous prime is 21475534603. The next prime is 21475534687. The reversal of 21475534639 is 93643557412.

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-21475534639 is a prime.

It is a super-2 number, since 2×21475534639² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21475534592 and 21475534601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21475534739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 734512 + ... + 763189.

It is an arithmetic number, because the mean of its divisors is an integer number (2893560264).

Almost surely, 2^21475534639 is an apocalyptic number.

21475534639 is a deficient number, since it is larger than the sum of its proper divisors (1672947473).

21475534639 is a wasteful number, since it uses less digits than its factorization.

21475534639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1498817.

The product of its digits is 2721600, while the sum is 49.

The spelling of 21475534639 in words is "twenty-one billion, four hundred seventy-five million, five hundred thirty-four thousand, six hundred thirty-nine".