21550704 has 80 divisors (see below), whose sum is σ = 65710080. Its totient is φ = 5955840.

The previous prime is 21550691. The next prime is 21550777. The reversal of 21550704 is 40705512.

21550704 = 127² + 128² + ... + 405².

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 15 ways as a sum of consecutive naturals, for example, 9382 + ... + 11450.

It is an arithmetic number, because the mean of its divisors is an integer number (821376).

Almost surely, 2^21550704 is an apocalyptic number.

21550704 is a gapful number since it is divisible by the number (24) 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 21550704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32855040).

21550704 is an abundant number, since it is smaller than the sum of its proper divisors (44159376).

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

21550704 is a wasteful number, since it uses less digits than its factorization.

21550704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2118 (or 2112 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 21550704 is about 4642.2735809084. The cubic root of 21550704 is about 278.2833058958.

It can be divided in two parts, 21 and 550704, that added together give a triangular number (550725 = T₁₀₄₉).

The spelling of 21550704 in words is "twenty-one million, five hundred fifty thousand, seven hundred four".