561557020 has 12 divisors (see below), whose sum is σ = 1179269784. Its totient is φ = 224622800.

The previous prime is 561556973. The next prime is 561557023. The reversal of 561557020 is 20755165.

It is a super-2 number, since 2×561557020² = 630692573422560800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561557023) 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, 14038906 + ... + 14038945.

It is an arithmetic number, because the mean of its divisors is an integer number (98272482).

Almost surely, 2^561557020 is an apocalyptic number.

It is an amenable number.

561557020 is an abundant number, since it is smaller than the sum of its proper divisors (617712764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561557020 is a wasteful number, since it uses less digits than its factorization.

561557020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28077860 (or 28077858 counting only the distinct ones).

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 561557020 is about 23697.1943486988. The cubic root of 561557020 is about 825.0202725352.

The spelling of 561557020 in words is "five hundred sixty-one million, five hundred fifty-seven thousand, twenty".