21045477 has 8 divisors (see below), whose sum is σ = 28536480. Its totient is φ = 13792400.

The previous prime is 21045469. The next prime is 21045481. The reversal of 21045477 is 77454012.

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

It is a cyclic number.

It is not a de Polignac number, because 21045477 - 2³ = 21045469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21045457) 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, 59274 + ... + 59627.

It is an arithmetic number, because the mean of its divisors is an integer number (3567060).

Almost surely, 2^21045477 is an apocalyptic number.

It is an amenable number.

21045477 is a deficient number, since it is larger than the sum of its proper divisors (7491003).

21045477 is a wasteful number, since it uses less digits than its factorization.

21045477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118963.

The product of its (nonzero) digits is 7840, while the sum is 30.

The square root of 21045477 is about 4587.5349589949. The cubic root of 21045477 is about 276.0914289618.

Adding to 21045477 its reverse (77454012), we get a palindrome (98499489).

The spelling of 21045477 in words is "twenty-one million, forty-five thousand, four hundred seventy-seven".