1561325651 has 2 divisors, whose sum is σ = 1561325652. Its totient is φ = 1561325650.

The previous prime is 1561325599. The next prime is 1561325663. The reversal of 1561325651 is 1565231651.

It is a strong prime.

It is an emirp because it is prime and its reverse (1565231651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1561325651 - 2⁶ = 1561325587 is a prime.

It is not a weakly prime, because it can be changed into another prime (1561325351) 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, 780662825 + 780662826.

It is an arithmetic number, because the mean of its divisors is an integer number (780662826).

Almost surely, 2^1561325651 is an apocalyptic number.

1561325651 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561325651 is an equidigital number, since it uses as much as digits as its factorization.

1561325651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27000, while the sum is 35.

The square root of 1561325651 is about 39513.6134895304. The cubic root of 1561325651 is about 1160.1064237971.

The spelling of 1561325651 in words is "one billion, five hundred sixty-one million, three hundred twenty-five thousand, six hundred fifty-one".