1200515551 has 4 divisors (see below), whose sum is σ = 1263700600. Its totient is φ = 1137330504.

The previous prime is 1200515483. The next prime is 1200515557. The reversal of 1200515551 is 1555150021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1555150021 = 17 ⋅91479413.

It is a cyclic number.

It is not a de Polignac number, because 1200515551 - 2¹³ = 1200507359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200515557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31592496 + ... + 31592533.

It is an arithmetic number, because the mean of its divisors is an integer number (315925150).

Almost surely, 2^1200515551 is an apocalyptic number.

1200515551 is a deficient number, since it is larger than the sum of its proper divisors (63185049).

1200515551 is an equidigital number, since it uses as much as digits as its factorization.

1200515551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63185048.

The product of its (nonzero) digits is 1250, while the sum is 25.

The square root of 1200515551 is about 34648.4566900172. The cubic root of 1200515551 is about 1062.8107292518.

Adding to 1200515551 its reverse (1555150021), we get a palindrome (2755665572).

It can be divided in two parts, 12005 and 15551, that added together give a square (27556 = 166²).

The spelling of 1200515551 in words is "one billion, two hundred million, five hundred fifteen thousand, five hundred fifty-one".