561387031 has 4 divisors (see below), whose sum is σ = 561751000. Its totient is φ = 561023064.

The previous prime is 561386983. The next prime is 561387049. The reversal of 561387031 is 130783165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130783165 = 5 ⋅26156633.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561387031 is a prime.

It is a super-2 number, since 2×561387031² = 630310797149989922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561387061) 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, 179661 + ... + 182758.

It is an arithmetic number, because the mean of its divisors is an integer number (140437750).

Almost surely, 2^561387031 is an apocalyptic number.

561387031 is a deficient number, since it is larger than the sum of its proper divisors (363969).

561387031 is a wasteful number, since it uses less digits than its factorization.

561387031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363968.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 561387031 is about 23693.6073868037. The cubic root of 561387031 is about 824.9370168018.

The spelling of 561387031 in words is "five hundred sixty-one million, three hundred eighty-seven thousand, thirty-one".