1551455261 has 2 divisors, whose sum is σ = 1551455262. Its totient is φ = 1551455260.

The previous prime is 1551455239. The next prime is 1551455263. The reversal of 1551455261 is 1625541551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1447802500 + 103652761 = 38050^2 + 10181^2 .

It is an emirp because it is prime and its reverse (1625541551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1551455261 - 2⁶ = 1551455197 is a prime.

It is a super-3 number, since 3×1551455261³ (a number of 29 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 1551455263, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1551455263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775727630 + 775727631.

It is an arithmetic number, because the mean of its divisors is an integer number (775727631).

Almost surely, 2^1551455261 is an apocalyptic number.

It is an amenable number.

1551455261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551455261 is an equidigital number, since it uses as much as digits as its factorization.

1551455261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30000, while the sum is 35.

The square root of 1551455261 is about 39388.5168672292. The cubic root of 1551455261 is about 1157.6566001211.

The spelling of 1551455261 in words is "one billion, five hundred fifty-one million, four hundred fifty-five thousand, two hundred sixty-one".