21415254 has 48 divisors (see below), whose sum is σ = 52005888. Its totient is φ = 5850768.

The previous prime is 21415249. The next prime is 21415307. The reversal of 21415254 is 45251412.

It is a super-2 number, since 2×21415254² = 917226207769032, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5179 + ... + 8345.

It is an arithmetic number, because the mean of its divisors is an integer number (1083456).

Almost surely, 2^21415254 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21415254, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26002944).

21415254 is an abundant number, since it is smaller than the sum of its proper divisors (30590634).

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

21415254 is a wasteful number, since it uses less digits than its factorization.

21415254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3209 (or 3202 counting only the distinct ones).

The product of its digits is 1600, while the sum is 24.

The square root of 21415254 is about 4627.6618286128. The cubic root of 21415254 is about 277.6990601600.

Adding to 21415254 its reverse (45251412), we get a palindrome (66666666).

The spelling of 21415254 in words is "twenty-one million, four hundred fifteen thousand, two hundred fifty-four".