21477955 has 8 divisors (see below), whose sum is σ = 25823952. Its totient is φ = 17148768.

The previous prime is 21477913. The next prime is 21477959. The reversal of 21477955 is 55977412.

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 21477955 - 2¹¹ = 21475907 is a prime.

It is a super-2 number, since 2×21477955² = 922605101964050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21477959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1192 + ... + 6661.

It is an arithmetic number, because the mean of its divisors is an integer number (3227994).

Almost surely, 2^21477955 is an apocalyptic number.

21477955 is a deficient number, since it is larger than the sum of its proper divisors (4345997).

21477955 is an equidigital number, since it uses as much as digits as its factorization.

21477955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8405.

The product of its digits is 88200, while the sum is 40.

The square root of 21477955 is about 4634.4314645920. The cubic root of 21477955 is about 277.9698179886.

The spelling of 21477955 in words is "twenty-one million, four hundred seventy-seven thousand, nine hundred fifty-five".