20156243251 has 2 divisors, whose sum is σ = 20156243252. Its totient is φ = 20156243250.

The previous prime is 20156243213. The next prime is 20156243287. The reversal of 20156243251 is 15234265102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20156243251 - 2¹³ = 20156235059 is a prime.

It is not a weakly prime, because it can be changed into another prime (20156243291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10078121625 + 10078121626.

It is an arithmetic number, because the mean of its divisors is an integer number (10078121626).

Almost surely, 2^20156243251 is an apocalyptic number.

20156243251 is a deficient number, since it is larger than the sum of its proper divisors (1).

20156243251 is an equidigital number, since it uses as much as digits as its factorization.

20156243251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 31.

The spelling of 20156243251 in words is "twenty billion, one hundred fifty-six million, two hundred forty-three thousand, two hundred fifty-one".