561122987 has 4 divisors (see below), whose sum is σ = 564223296. Its totient is φ = 558022680.

The previous prime is 561122983. The next prime is 561123023. The reversal of 561122987 is 789221165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789221165 = 5 ⋅157844233.

It is a cyclic number.

It is not a de Polignac number, because 561122987 - 2² = 561122983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561122983) 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, 1549883 + ... + 1550244.

It is an arithmetic number, because the mean of its divisors is an integer number (141055824).

Almost surely, 2^561122987 is an apocalyptic number.

561122987 is a deficient number, since it is larger than the sum of its proper divisors (3100309).

561122987 is a wasteful number, since it uses less digits than its factorization.

561122987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3100308.

The product of its digits is 60480, while the sum is 41.

The square root of 561122987 is about 23688.0346799814. The cubic root of 561122987 is about 824.8076622944.

The spelling of 561122987 in words is "five hundred sixty-one million, one hundred twenty-two thousand, nine hundred eighty-seven".