121651261 has 2 divisors, whose sum is σ = 121651262. Its totient is φ = 121651260.

The previous prime is 121651253. The next prime is 121651273. The reversal of 121651261 is 162156121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120868036 + 783225 = 10994^2 + 885^2 .

It is an emirp because it is prime and its reverse (162156121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121651261 - 2³ = 121651253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121651291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60825630 + 60825631.

It is an arithmetic number, because the mean of its divisors is an integer number (60825631).

Almost surely, 2^121651261 is an apocalyptic number.

It is an amenable number.

121651261 is a deficient number, since it is larger than the sum of its proper divisors (1).

121651261 is an equidigital number, since it uses as much as digits as its factorization.

121651261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 25.

The square root of 121651261 is about 11029.5630466488. The cubic root of 121651261 is about 495.4945382382.

The spelling of 121651261 in words is "one hundred twenty-one million, six hundred fifty-one thousand, two hundred sixty-one".