51616620 has 144 divisors (see below), whose sum is σ = 172972800. Its totient is φ = 12355200.

The previous prime is 51616583. The next prime is 51616667. The reversal of 51616620 is 2661615.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 259281 + ... + 259479.

It is an arithmetic number, because the mean of its divisors is an integer number (1201200).

Almost surely, 2^51616620 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 51616620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86486400).

51616620 is an abundant number, since it is smaller than the sum of its proper divisors (121356180).

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

51616620 is a wasteful number, since it uses less digits than its factorization.

51616620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 51616620 is about 7184.4707529504. The cubic root of 51616620 is about 372.3315635641.

It can be divided in two parts, 5161 and 6620, that added together give a triangular number (11781 = T₁₅₃).

The spelling of 51616620 in words is "fifty-one million, six hundred sixteen thousand, six hundred twenty".