20439956 has 6 divisors (see below), whose sum is σ = 35769930. Its totient is φ = 10219976.

The previous prime is 20439931. The next prime is 20439959. The reversal of 20439956 is 65993402.

It can be written as a sum of positive squares in only one way, i.e., 20340100 + 99856 = 4510^2 + 316^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20439959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2554991 + ... + 2554998.

It is an arithmetic number, because the mean of its divisors is an integer number (5961655).

Almost surely, 2^20439956 is an apocalyptic number.

It is an amenable number.

20439956 is a deficient number, since it is larger than the sum of its proper divisors (15329974).

20439956 is a wasteful number, since it uses less digits than its factorization.

20439956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5109993 (or 5109991 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 20439956 is about 4521.0569560668. The cubic root of 20439956 is about 273.4177166922.

The spelling of 20439956 in words is "twenty million, four hundred thirty-nine thousand, nine hundred fifty-six".