1561262141 has 4 divisors (see below), whose sum is σ = 1576720284. Its totient is φ = 1545804000.

The previous prime is 1561262123. The next prime is 1561262147. The reversal of 1561262141 is 1412621651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1412621651 = 7 ⋅201803093.

It can be written as a sum of positive squares in 2 ways, for example, as 1462756516 + 98505625 = 38246^2 + 9925^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561262141 - 2¹⁴ = 1561245757 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 (1561262147) 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, 7728920 + ... + 7729121.

It is an arithmetic number, because the mean of its divisors is an integer number (394180071).

Almost surely, 2^1561262141 is an apocalyptic number.

It is an amenable number.

1561262141 is a deficient number, since it is larger than the sum of its proper divisors (15458143).

1561262141 is a wasteful number, since it uses less digits than its factorization.

1561262141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15458142.

The product of its digits is 2880, while the sum is 29.

The square root of 1561262141 is about 39512.8098342803. The cubic root of 1561262141 is about 1160.0906937116.

Adding to 1561262141 its reverse (1412621651), we get a palindrome (2973883792).

The spelling of 1561262141 in words is "one billion, five hundred sixty-one million, two hundred sixty-two thousand, one hundred forty-one".