201621611251 has 2 divisors, whose sum is σ = 201621611252. Its totient is φ = 201621611250.

The previous prime is 201621611221. The next prime is 201621611263. The reversal of 201621611251 is 152116126102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201621611251 - 2²⁵ = 201588056819 is a prime.

It is not a weakly prime, because it can be changed into another prime (201621611201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100810805625 + 100810805626.

It is an arithmetic number, because the mean of its divisors is an integer number (100810805626).

Almost surely, 2^201621611251 is an apocalyptic number.

201621611251 is a deficient number, since it is larger than the sum of its proper divisors (1).

201621611251 is an equidigital number, since it uses as much as digits as its factorization.

201621611251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 28.

Adding to 201621611251 its reverse (152116126102), we get a palindrome (353737737353).

The spelling of 201621611251 in words is "two hundred one billion, six hundred twenty-one million, six hundred eleven thousand, two hundred fifty-one".