1551545521 has 2 divisors, whose sum is σ = 1551545522. Its totient is φ = 1551545520.

The previous prime is 1551545509. The next prime is 1551545533. The reversal of 1551545521 is 1255451551.

It is a balanced prime because it is at equal distance from previous prime (1551545509) and next prime (1551545533).

It can be written as a sum of positive squares in only one way, i.e., 1476480625 + 75064896 = 38425^2 + 8664^2 .

It is a cyclic number.

It is not a de Polignac number, because 1551545521 - 2²³ = 1543156913 is a prime.

It is a super-2 number, since 2×1551545521² = 4814587007470322882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1551545581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775772760 + 775772761.

It is an arithmetic number, because the mean of its divisors is an integer number (775772761).

Almost surely, 2^1551545521 is an apocalyptic number.

It is an amenable number.

1551545521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551545521 is an equidigital number, since it uses as much as digits as its factorization.

1551545521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25000, while the sum is 34.

The square root of 1551545521 is about 39389.6626159707. The cubic root of 1551545521 is about 1157.6790495940.

The spelling of 1551545521 in words is "one billion, five hundred fifty-one million, five hundred forty-five thousand, five hundred twenty-one".