21079100 has 36 divisors (see below), whose sum is σ = 52277904. Its totient is φ = 7226880.

The previous prime is 21079087. The next prime is 21079127. The reversal of 21079100 is 197012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14357 + ... + 15756.

It is an arithmetic number, because the mean of its divisors is an integer number (1452164).

Almost surely, 2^21079100 is an apocalyptic number.

21079100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21079100 is an abundant number, since it is smaller than the sum of its proper divisors (31198804).

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

21079100 is a wasteful number, since it uses less digits than its factorization.

21079100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30134 (or 30127 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 21079100 is about 4591.1981007140. The cubic root of 21079100 is about 276.2383818814.

The spelling of 21079100 in words is "twenty-one million, seventy-nine thousand, one hundred".