51429840 has 320 divisors, whose sum is σ = 209129472. Its totient is φ = 10222080.

The previous prime is 51429839. The next prime is 51429877. The reversal of 51429840 is 4892415.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2236069 + ... + 2236091.

Almost surely, 2^51429840 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 51429840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104564736).

51429840 is an abundant number, since it is smaller than the sum of its proper divisors (157699632).

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

51429840 is a wasteful number, since it uses less digits than its factorization.

51429840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 51429840 is about 7171.4601023780. The cubic root of 51429840 is about 371.8819141901.

The spelling of 51429840 in words is "fifty-one million, four hundred twenty-nine thousand, eight hundred forty".