1561001016149 has 4 divisors (see below), whose sum is σ = 1561013806860. Its totient is φ = 1560988225440.

The previous prime is 1561001016139. The next prime is 1561001016181. The reversal of 1561001016149 is 9416101001651.

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 1192861521124 + 368139495025 = 1092182^2 + 606745^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561001016149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561001016139) 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, 6210512 + ... + 6456969.

It is an arithmetic number, because the mean of its divisors is an integer number (390253451715).

Almost surely, 2^{1561001016149} is an apocalyptic number.

It is an amenable number.

1561001016149 is a deficient number, since it is larger than the sum of its proper divisors (12790711).

1561001016149 is a wasteful number, since it uses less digits than its factorization.

1561001016149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12790710.

The product of its (nonzero) digits is 6480, while the sum is 35.

The spelling of 1561001016149 in words is "one trillion, five hundred sixty-one billion, one million, sixteen thousand, one hundred forty-nine".