1551327649 has 4 divisors (see below), whose sum is σ = 1580598036. Its totient is φ = 1522057264.

The previous prime is 1551327611. The next prime is 1551327671. The reversal of 1551327649 is 9467231551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1152127249 + 399200400 = 33943^2 + 19980^2 .

It is a cyclic number.

It is not a de Polignac number, because 1551327649 - 2⁷ = 1551327521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1551327149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14635114 + ... + 14635219.

It is an arithmetic number, because the mean of its divisors is an integer number (395149509).

Almost surely, 2^1551327649 is an apocalyptic number.

It is an amenable number.

1551327649 is a deficient number, since it is larger than the sum of its proper divisors (29270387).

1551327649 is an equidigital number, since it uses as much as digits as its factorization.

1551327649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29270386.

The product of its digits is 226800, while the sum is 43.

The square root of 1551327649 is about 39386.8969201688. The cubic root of 1551327649 is about 1157.6248589706.

The spelling of 1551327649 in words is "one billion, five hundred fifty-one million, three hundred twenty-seven thousand, six hundred forty-nine".