21475028117 has 2 divisors, whose sum is σ = 21475028118. Its totient is φ = 21475028116.

The previous prime is 21475028089. The next prime is 21475028173. The reversal of 21475028117 is 71182057412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21318628081 + 156400036 = 146009^2 + 12506^2 .

It is a cyclic number.

It is not a de Polignac number, because 21475028117 - 2³⁰ = 20401286293 is a prime.

It is a super-2 number, since 2×21475028117² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21475028017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10737514058 + 10737514059.

It is an arithmetic number, because the mean of its divisors is an integer number (10737514059).

Almost surely, 2^21475028117 is an apocalyptic number.

It is an amenable number.

21475028117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21475028117 is an equidigital number, since it uses as much as digits as its factorization.

21475028117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31360, while the sum is 38.

The spelling of 21475028117 in words is "twenty-one billion, four hundred seventy-five million, twenty-eight thousand, one hundred seventeen".