55557557 has 4 divisors (see below), whose sum is σ = 60608256. Its totient is φ = 50506860.

The previous prime is 55557521. The next prime is 55557563. The reversal of 55557557 is 75575555.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 55557557 - 2¹² = 55553461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55557587) 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, 2525333 + ... + 2525354.

It is an arithmetic number, because the mean of its divisors is an integer number (15152064).

Almost surely, 2^55557557 is an apocalyptic number.

It is an amenable number.

55557557 is a deficient number, since it is larger than the sum of its proper divisors (5050699).

55557557 is a wasteful number, since it uses less digits than its factorization.

55557557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5050698.

The product of its digits is 765625, while the sum is 44.

The square root of 55557557 is about 7453.6941847650. The cubic root of 55557557 is about 381.5759962933.

The spelling of 55557557 in words is "fifty-five million, five hundred fifty-seven thousand, five hundred fifty-seven".