1156561623 has 12 divisors (see below), whose sum is σ = 1909244688. Its totient is φ = 660892320.

The previous prime is 1156561573. The next prime is 1156561639. The reversal of 1156561623 is 3261656511.

1156561623 is a `hidden beast` number, since 1 + 15 + 6 + 5 + 616 + 23 = 666.

It is not a de Polignac number, because 1156561623 - 2¹⁴ = 1156545239 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1156561643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9178998 + ... + 9179123.

It is an arithmetic number, because the mean of its divisors is an integer number (159103724).

Almost surely, 2^1156561623 is an apocalyptic number.

1156561623 is a deficient number, since it is larger than the sum of its proper divisors (752683065).

1156561623 is a wasteful number, since it uses less digits than its factorization.

1156561623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18358134 (or 18358131 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 1156561623 is about 34008.2581588649. The cubic root of 1156561623 is about 1049.6783967447.

The spelling of 1156561623 in words is "one billion, one hundred fifty-six million, five hundred sixty-one thousand, six hundred twenty-three".