20125221409 has 2 divisors, whose sum is σ = 20125221410. Its totient is φ = 20125221408.

The previous prime is 20125221383. The next prime is 20125221449. The reversal of 20125221409 is 90412252102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19389727009 + 735494400 = 139247^2 + 27120^2 .

It is a cyclic number.

It is not a de Polignac number, because 20125221409 - 2⁵ = 20125221377 is a prime.

It is a super-2 number, since 2×20125221409² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20125221449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10062610704 + 10062610705.

It is an arithmetic number, because the mean of its divisors is an integer number (10062610705).

Almost surely, 2^20125221409 is an apocalyptic number.

It is an amenable number.

20125221409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20125221409 is an equidigital number, since it uses as much as digits as its factorization.

20125221409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The spelling of 20125221409 in words is "twenty billion, one hundred twenty-five million, two hundred twenty-one thousand, four hundred nine".