20656407 has 8 divisors (see below), whose sum is σ = 27592560. Its totient is φ = 13745600.

The previous prime is 20656393. The next prime is 20656409. The reversal of 20656407 is 70465602.

20656407 = T₂₁₃₈ + T₂₁₃₉ + ... + T₂₁₄₆.

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 20656407 - 2¹² = 20652311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20656409) 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 7 ways as a sum of consecutive naturals, for example, 4344 + ... + 7757.

It is an arithmetic number, because the mean of its divisors is an integer number (3449070).

Almost surely, 2^20656407 is an apocalyptic number.

20656407 is a deficient number, since it is larger than the sum of its proper divisors (6936153).

20656407 is a wasteful number, since it uses less digits than its factorization.

20656407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12673.

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 20656407 is about 4544.9320126928. The cubic root of 20656407 is about 274.3794580907.

The spelling of 20656407 in words is "twenty million, six hundred fifty-six thousand, four hundred seven".