21341720 has 16 divisors (see below), whose sum is σ = 48018960. Its totient is φ = 8536672.

The previous prime is 21341687. The next prime is 21341729. The reversal of 21341720 is 2714312.

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

It is a junction number, because it is equal to n+sod(n) for n = 21341692 and 21341701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21341729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266732 + ... + 266811.

It is an arithmetic number, because the mean of its divisors is an integer number (3001185).

Almost surely, 2^21341720 is an apocalyptic number.

21341720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21341720 is an abundant number, since it is smaller than the sum of its proper divisors (26677240).

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

21341720 is a wasteful number, since it uses less digits than its factorization.

21341720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533554 (or 533550 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21341720 is about 4619.7099476049. The cubic root of 21341720 is about 277.3808486656.

The spelling of 21341720 in words is "twenty-one million, three hundred forty-one thousand, seven hundred twenty".