21741730 has 32 divisors (see below), whose sum is σ = 40352256. Its totient is φ = 8430144.

The previous prime is 21741689. The next prime is 21741743. The reversal of 21741730 is 3714712.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21741695 and 21741704.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78352 + ... + 78628.

It is an arithmetic number, because the mean of its divisors is an integer number (1261008).

Almost surely, 2^21741730 is an apocalyptic number.

21741730 is a deficient number, since it is larger than the sum of its proper divisors (18610526).

21741730 is a wasteful number, since it uses less digits than its factorization.

21741730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 21741730 is about 4662.8028051806. The cubic root of 21741730 is about 279.1031251636.

The spelling of 21741730 in words is "twenty-one million, seven hundred forty-one thousand, seven hundred thirty".