21475028101 has 4 divisors (see below), whose sum is σ = 21827077804. Its totient is φ = 21122978400.

The previous prime is 21475028089. The next prime is 21475028117. The reversal of 21475028101 is 10182057412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 515517025 + 20959511076 = 22705^2 + 144774^2 .

It is a cyclic number.

It is not a de Polignac number, because 21475028101 - 2²¹ = 21472930949 is a prime.

It is a super-2 number, since 2×21475028101² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21475028191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176024760 + ... + 176024881.

It is an arithmetic number, because the mean of its divisors is an integer number (5456769451).

Almost surely, 2^21475028101 is an apocalyptic number.

It is an amenable number.

21475028101 is a deficient number, since it is larger than the sum of its proper divisors (352049703).

21475028101 is an equidigital number, since it uses as much as digits as its factorization.

21475028101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352049702.

The product of its (nonzero) digits is 4480, while the sum is 31.

The spelling of 21475028101 in words is "twenty-one billion, four hundred seventy-five million, twenty-eight thousand, one hundred one".