1206661551 has 8 divisors (see below), whose sum is σ = 1664360880. Its totient is φ = 776701632.

The previous prime is 1206661549. The next prime is 1206661559. The reversal of 1206661551 is 1551666021.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1206661551 - 2¹ = 1206661549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1206661559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6934750 + ... + 6934923.

It is an arithmetic number, because the mean of its divisors is an integer number (208045110).

Almost surely, 2^1206661551 is an apocalyptic number.

1206661551 is a deficient number, since it is larger than the sum of its proper divisors (457699329).

1206661551 is a wasteful number, since it uses less digits than its factorization.

1206661551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13869705.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 1206661551 is about 34737.0342861909. The cubic root of 1206661551 is about 1064.6213179016.

The spelling of 1206661551 in words is "one billion, two hundred six million, six hundred sixty-one thousand, five hundred fifty-one".