21417477 has 8 divisors (see below), whose sum is σ = 29164416. Its totient is φ = 13974432.

The previous prime is 21417463. The next prime is 21417481. The reversal of 21417477 is 77471412.

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

It is not a de Polignac number, because 21417477 - 2⁷ = 21417349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21417437) 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 7 ways as a sum of consecutive naturals, for example, 75808 + ... + 76089.

It is an arithmetic number, because the mean of its divisors is an integer number (3645552).

Almost surely, 2^21417477 is an apocalyptic number.

It is an amenable number.

21417477 is a deficient number, since it is larger than the sum of its proper divisors (7746939).

21417477 is a wasteful number, since it uses less digits than its factorization.

21417477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151947.

The product of its digits is 10976, while the sum is 33.

The square root of 21417477 is about 4627.9020084699. The cubic root of 21417477 is about 277.7086686327.

Adding to 21417477 its reverse (77471412), we get a palindrome (98888889).

The spelling of 21417477 in words is "twenty-one million, four hundred seventeen thousand, four hundred seventy-seven".