20156401 has 2 divisors, whose sum is σ = 20156402. Its totient is φ = 20156400.

The previous prime is 20156369. The next prime is 20156419. The reversal of 20156401 is 10465102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16160400 + 3996001 = 4020^2 + 1999^2 .

It is a cyclic number.

It is not a de Polignac number, because 20156401 - 2⁵ = 20156369 is a prime.

It is not a weakly prime, because it can be changed into another prime (20156431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10078200 + 10078201.

It is an arithmetic number, because the mean of its divisors is an integer number (10078201).

Almost surely, 2^20156401 is an apocalyptic number.

It is an amenable number.

20156401 is a deficient number, since it is larger than the sum of its proper divisors (1).

20156401 is an equidigital number, since it uses as much as digits as its factorization.

20156401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 20156401 is about 4489.5880657361. The cubic root of 20156401 is about 272.1474879550.

The spelling of 20156401 in words is "twenty million, one hundred fifty-six thousand, four hundred one".