21367740 has 24 divisors (see below), whose sum is σ = 59829840. Its totient is φ = 5698048.

The previous prime is 21367739. The next prime is 21367741. The reversal of 21367740 is 4776312.

It is an interprime number because it is at equal distance from previous prime (21367739) and next prime (21367741).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21367698 and 21367707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21367741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178005 + ... + 178124.

It is an arithmetic number, because the mean of its divisors is an integer number (2492910).

Almost surely, 2^21367740 is an apocalyptic number.

21367740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21367740 is an abundant number, since it is smaller than the sum of its proper divisors (38462100).

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

21367740 is a wasteful number, since it uses less digits than its factorization.

21367740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356141 (or 356139 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 30.

The square root of 21367740 is about 4622.5252838681. The cubic root of 21367740 is about 277.4935312184.

The spelling of 21367740 in words is "twenty-one million, three hundred sixty-seven thousand, seven hundred forty".