20401956 has 30 divisors (see below), whose sum is σ = 53335590. Its totient is φ = 6800544.

The previous prime is 20401951. The next prime is 20401957. The reversal of 20401956 is 65910402.

It can be written as a sum of positive squares in only one way, i.e., 17892900 + 2509056 = 4230^2 + 1584^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20401951) 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 9 ways as a sum of consecutive naturals, for example, 31161 + ... + 31808.

It is an arithmetic number, because the mean of its divisors is an integer number (1777853).

Almost surely, 2^20401956 is an apocalyptic number.

It is an amenable number.

20401956 is an abundant number, since it is smaller than the sum of its proper divisors (32933634).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20401956 is a wasteful number, since it uses less digits than its factorization.

20401956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62985 (or 62974 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20401956 is about 4516.8524439038. The cubic root of 20401956 is about 273.2481742772.

The spelling of 20401956 in words is "twenty million, four hundred one thousand, nine hundred fifty-six".