21707079 has 12 divisors (see below), whose sum is σ = 30746664. Its totient is φ = 13619584.

The previous prime is 21707071. The next prime is 21707083. The reversal of 21707079 is 97070712.

21707079 = T₂₃₄ + T₂₃₅ + ... + T₅₂₂.

It is not a de Polignac number, because 21707079 - 2³ = 21707071 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21707071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11652 + ... + 13385.

It is an arithmetic number, because the mean of its divisors is an integer number (2562222).

Almost surely, 2^21707079 is an apocalyptic number.

21707079 is a deficient number, since it is larger than the sum of its proper divisors (9039585).

21707079 is a wasteful number, since it uses less digits than its factorization.

21707079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25074 (or 25057 counting only the distinct ones).

The product of its (nonzero) digits is 6174, while the sum is 33.

The square root of 21707079 is about 4659.0856399083. The cubic root of 21707079 is about 278.9547722835.

The spelling of 21707079 in words is "twenty-one million, seven hundred seven thousand, seventy-nine".