21377400 has 192 divisors, whose sum is σ = 74995200. Its totient is φ = 4992000.

The previous prime is 21377399. The next prime is 21377417. The reversal of 21377400 is 477312.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 270561 + ... + 270639.

It is an arithmetic number, because the mean of its divisors is an integer number (390600).

Almost surely, 2^21377400 is an apocalyptic number.

21377400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21377400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37497600).

21377400 is an abundant number, since it is smaller than the sum of its proper divisors (53617800).

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

21377400 is a wasteful number, since it uses less digits than its factorization.

21377400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 24.

The square root of 21377400 is about 4623.5700492152. The cubic root of 21377400 is about 277.5353416558.

The spelling of 21377400 in words is "twenty-one million, three hundred seventy-seven thousand, four hundred".