51861450 has 96 divisors (see below), whose sum is σ = 139991040. Its totient is φ = 12657600.

The previous prime is 51861449. The next prime is 51861451. The reversal of 51861450 is 5416815.

It is an interprime number because it is at equal distance from previous prime (51861449) and next prime (51861451).

It is a super-2 number, since 2×51861450² = 5379219992205000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (51861451) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 88057 + ... + 88643.

It is an arithmetic number, because the mean of its divisors is an integer number (1458240).

Almost surely, 2^51861450 is an apocalyptic number.

51861450 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 51861450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69995520).

51861450 is an abundant number, since it is smaller than the sum of its proper divisors (88129590).

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

51861450 is a wasteful number, since it uses less digits than its factorization.

51861450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652 (or 647 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 51861450 is about 7201.4894292778. The cubic root of 51861450 is about 372.9193211980.

The spelling of 51861450 in words is "fifty-one million, eight hundred sixty-one thousand, four hundred fifty".