21477446637 has 16 divisors (see below), whose sum is σ = 28711986240. Its totient is φ = 14280652800.

The previous prime is 21477446633. The next prime is 21477446681. The reversal of 21477446637 is 73664477412.

It is not a de Polignac number, because 21477446637 - 2² = 21477446633 is a prime.

It is a super-2 number, since 2×21477446637² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21477446637.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21477446633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1957914 + ... + 1968852.

It is an arithmetic number, because the mean of its divisors is an integer number (1794499140).

Almost surely, 2^21477446637 is an apocalyptic number.

It is an amenable number.

21477446637 is a deficient number, since it is larger than the sum of its proper divisors (7234539603).

21477446637 is a wasteful number, since it uses less digits than its factorization.

21477446637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12604.

The product of its digits is 4741632, while the sum is 51.

The spelling of 21477446637 in words is "twenty-one billion, four hundred seventy-seven million, four hundred forty-six thousand, six hundred thirty-seven".