51605442 has 72 divisors (see below), whose sum is σ = 132614976. Its totient is φ = 14206752.

The previous prime is 51605441. The next prime is 51605443. The reversal of 51605442 is 24450615.

51605442 is a `hidden beast` number, since 51 + 605 + 4 + 4 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (51605441) and next prime (51605443).

It is not an unprimeable number, because it can be changed into a prime (51605441) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 105723 + ... + 106209.

Almost surely, 2^51605442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51605442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66307488).

51605442 is an abundant number, since it is smaller than the sum of its proper divisors (81009534).

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

51605442 is a wasteful number, since it uses less digits than its factorization.

51605442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 560 (or 528 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 51605442 is about 7183.6927829634. The cubic root of 51605442 is about 372.3046844782.

The spelling of 51605442 in words is "fifty-one million, six hundred five thousand, four hundred forty-two".