51099840 has 168 divisors, whose sum is σ = 191859408. Its totient is φ = 12380160.

The previous prime is 51099833. The next prime is 51099871. The reversal of 51099840 is 4899015.

It is a super-2 number, since 2×51099840² = 5222387296051200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51099795 and 51099804.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 30874 + ... + 32486.

Almost surely, 2^51099840 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 51099840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95929704).

51099840 is an abundant number, since it is smaller than the sum of its proper divisors (140759568).

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

51099840 is a wasteful number, since it uses less digits than its factorization.

51099840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647 (or 1634 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 51099840 is about 7148.4152089816. The cubic root of 51099840 is about 371.0848124067.

The spelling of 51099840 in words is "fifty-one million, ninety-nine thousand, eight hundred forty".