20956947 has 16 divisors (see below), whose sum is σ = 30801792. Its totient is φ = 12568320.

The previous prime is 20956939. The next prime is 20956951. The reversal of 20956947 is 74965902.

It is not a de Polignac number, because 20956947 - 2³ = 20956939 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20956899 and 20956908.

It is not an unprimeable number, because it can be changed into a prime (20956907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73 + ... + 6474.

It is an arithmetic number, because the mean of its divisors is an integer number (1925112).

Almost surely, 2^20956947 is an apocalyptic number.

20956947 is a deficient number, since it is larger than the sum of its proper divisors (9844845).

20956947 is a wasteful number, since it uses less digits than its factorization.

20956947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6658.

The product of its (nonzero) digits is 136080, while the sum is 42.

The square root of 20956947 is about 4577.8758174507. The cubic root of 20956947 is about 275.7037490237.

The spelling of 20956947 in words is "twenty million, nine hundred fifty-six thousand, nine hundred forty-seven".