21475542 has 32 divisors (see below), whose sum is σ = 47309184. Its totient is φ = 6444800.

The previous prime is 21475511. The next prime is 21475543. The reversal of 21475542 is 24557412.

It is a super-2 number, since 2×21475542² = 922397808387528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21475543) 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 15 ways as a sum of consecutive naturals, for example, 5542 + ... + 8582.

It is an arithmetic number, because the mean of its divisors is an integer number (1478412).

Almost surely, 2^21475542 is an apocalyptic number.

21475542 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21475542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23654592).

21475542 is an abundant number, since it is smaller than the sum of its proper divisors (25833642).

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

21475542 is a wasteful number, since it uses less digits than its factorization.

21475542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3164.

The product of its digits is 11200, while the sum is 30.

The square root of 21475542 is about 4634.1711232970. The cubic root of 21475542 is about 277.9594078372.

The spelling of 21475542 in words is "twenty-one million, four hundred seventy-five thousand, five hundred forty-two".