21477428 has 12 divisors (see below), whose sum is σ = 42954912. Its totient is φ = 9204600.

The previous prime is 21477419. The next prime is 21477439. The reversal of 21477428 is 82477412.

It is a happy number.

21477428 is an admirable number.

It is a super-2 number, since 2×21477428² = 922559826990368, which contains 22 as substring.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 383498 + ... + 383553.

It is an arithmetic number, because the mean of its divisors is an integer number (3579576).

Almost surely, 2^21477428 is an apocalyptic number.

21477428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21477428 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21477428 is a wasteful number, since it uses less digits than its factorization.

21477428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767062 (or 767060 counting only the distinct ones).

The product of its digits is 25088, while the sum is 35.

The square root of 21477428 is about 4634.3746072151. The cubic root of 21477428 is about 277.9675444746.

The spelling of 21477428 in words is "twenty-one million, four hundred seventy-seven thousand, four hundred twenty-eight".