21472120117 has 24 divisors (see below), whose sum is σ = 25380153792. Its totient is φ = 18109224000.

The previous prime is 21472120081. The next prime is 21472120123. The reversal of 21472120117 is 71102127412.

It is a happy number.

It is not a de Polignac number, because 21472120117 - 2²⁷ = 21337902389 is a prime.

It is a super-2 number, since 2×21472120117² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21472120217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1813617 + ... + 1825417.

It is an arithmetic number, because the mean of its divisors is an integer number (1057506408).

Almost surely, 2^21472120117 is an apocalyptic number.

It is an amenable number.

21472120117 is a deficient number, since it is larger than the sum of its proper divisors (3908033675).

21472120117 is a wasteful number, since it uses less digits than its factorization.

21472120117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12409 (or 12402 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 28.

Adding to 21472120117 its reverse (71102127412), we get a palindrome (92574247529).

The spelling of 21472120117 in words is "twenty-one billion, four hundred seventy-two million, one hundred twenty thousand, one hundred seventeen".