1561338375 has 32 divisors (see below), whose sum is σ = 2623355904. Its totient is φ = 824608800.

The previous prime is 1561338347. The next prime is 1561338377. The reversal of 1561338375 is 5738331651.

It is not a de Polignac number, because 1561338375 - 2¹¹ = 1561336327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561338377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18414 + ... + 58836.

It is an arithmetic number, because the mean of its divisors is an integer number (81979872).

Almost surely, 2^1561338375 is an apocalyptic number.

1561338375 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1561338375 is a deficient number, since it is larger than the sum of its proper divisors (1062017529).

1561338375 is a wasteful number, since it uses less digits than its factorization.

1561338375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40544 (or 40534 counting only the distinct ones).

The product of its digits is 226800, while the sum is 42.

The square root of 1561338375 is about 39513.7744970029. The cubic root of 1561338375 is about 1160.1095752119.

The spelling of 1561338375 in words is "one billion, five hundred sixty-one million, three hundred thirty-eight thousand, three hundred seventy-five".