51009557 has 4 divisors (see below), whose sum is σ = 51024480. Its totient is φ = 50994636.

The previous prime is 51009529. The next prime is 51009583. The reversal of 51009557 is 75590015.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 75590015 = 5 ⋅15118003.

It is a cyclic number.

It is not a de Polignac number, because 51009557 - 2¹⁸ = 50747413 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 (51009587) 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, 494 + ... + 10112.

It is an arithmetic number, because the mean of its divisors is an integer number (12756120).

Almost surely, 2^51009557 is an apocalyptic number.

It is an amenable number.

51009557 is a deficient number, since it is larger than the sum of its proper divisors (14923).

51009557 is an equidigital number, since it uses as much as digits as its factorization.

51009557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14922.

The product of its (nonzero) digits is 7875, while the sum is 32.

The square root of 51009557 is about 7142.0975210368. The cubic root of 51009557 is about 370.8661398349.

The spelling of 51009557 in words is "fifty-one million, nine thousand, five hundred fifty-seven".