21624141 has 48 divisors (see below), whose sum is σ = 37559808. Its totient is φ = 10936800.

The previous prime is 21624137. The next prime is 21624157. The reversal of 21624141 is 14142612.

It is a happy number.

It is not a de Polignac number, because 21624141 - 2² = 21624137 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21624101) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 69376 + ... + 69686.

It is an arithmetic number, because the mean of its divisors is an integer number (782496).

Almost surely, 2^21624141 is an apocalyptic number.

21624141 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21624141 is a deficient number, since it is larger than the sum of its proper divisors (15935667).

21624141 is a wasteful number, since it uses less digits than its factorization.

21624141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382 (or 375 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 21624141 is about 4650.1764482652. The cubic root of 21624141 is about 278.5990437919.

Adding to 21624141 its reverse (14142612), we get a palindrome (35766753).

The spelling of 21624141 in words is "twenty-one million, six hundred twenty-four thousand, one hundred forty-one".