21740100 has 36 divisors (see below), whose sum is σ = 62902224. Its totient is φ = 5797280.

The previous prime is 21740063. The next prime is 21740101. The reversal of 21740100 is 104712.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21740100.

It is not an unprimeable number, because it can be changed into a prime (21740101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35934 + ... + 36533.

It is an arithmetic number, because the mean of its divisors is an integer number (1747284).

Almost surely, 2^21740100 is an apocalyptic number.

21740100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21740100 is an abundant number, since it is smaller than the sum of its proper divisors (41162124).

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

21740100 is a wasteful number, since it uses less digits than its factorization.

21740100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72484 (or 72477 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 21740100 is about 4662.6280143284. The cubic root of 21740100 is about 279.0961501059.

Adding to 21740100 its reverse (104712), we get a palindrome (21844812).

The spelling of 21740100 in words is "twenty-one million, seven hundred forty thousand, one hundred".