21457312177 has 8 divisors (see below), whose sum is σ = 24533741376. Its totient is φ = 18383657712.

The previous prime is 21457312171. The next prime is 21457312187. The reversal of 21457312177 is 77121375412.

It is a happy number.

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

It is not a de Polignac number, because 21457312177 - 2³¹ = 19309828529 is a prime.

It is a super-2 number, since 2×21457312177² (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 (21457312171) 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, 677083 + ... + 708064.

It is an arithmetic number, because the mean of its divisors is an integer number (3066717672).

Almost surely, 2^21457312177 is an apocalyptic number.

It is an amenable number.

21457312177 is a deficient number, since it is larger than the sum of its proper divisors (3076429199).

21457312177 is a wasteful number, since it uses less digits than its factorization.

21457312177 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1387367.

The product of its digits is 82320, while the sum is 40.

Adding to 21457312177 its reverse (77121375412), we get a palindrome (98578687589).

The spelling of 21457312177 in words is "twenty-one billion, four hundred fifty-seven million, three hundred twelve thousand, one hundred seventy-seven".