51064640 has 112 divisors (see below), whose sum is σ = 134965440. Its totient is φ = 18247680.

The previous prime is 51064631. The next prime is 51064649. The reversal of 51064640 is 4646015.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51064631) and next prime (51064649).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51064649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 313199 + ... + 313361.

Almost surely, 2^51064640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51064640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67482720).

51064640 is an abundant number, since it is smaller than the sum of its proper divisors (83900800).

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

51064640 is a wasteful number, since it uses less digits than its factorization.

51064640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 51064640 is about 7145.9527006551. The cubic root of 51064640 is about 370.9995858787. Note that the first 3 decimals are identical.

The spelling of 51064640 in words is "fifty-one million, sixty-four thousand, six hundred forty".