21355707 has 8 divisors (see below), whose sum is σ = 29712384. Its totient is φ = 13618088.

The previous prime is 21355693. The next prime is 21355717. The reversal of 21355707 is 70755312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21355707 - 2¹⁴ = 21339323 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21355717) 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, 154683 + ... + 154820.

It is an arithmetic number, because the mean of its divisors is an integer number (3714048).

Almost surely, 2^21355707 is an apocalyptic number.

21355707 is a deficient number, since it is larger than the sum of its proper divisors (8356677).

21355707 is a wasteful number, since it uses less digits than its factorization.

21355707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309529.

The product of its (nonzero) digits is 7350, while the sum is 30.

The square root of 21355707 is about 4621.2235392805. The cubic root of 21355707 is about 277.4414323278.

The spelling of 21355707 in words is "twenty-one million, three hundred fifty-five thousand, seven hundred seven".