51439620 has 192 divisors, whose sum is σ = 165473280. Its totient is φ = 11870208.

The previous prime is 51439613. The next prime is 51439651. The reversal of 51439620 is 2693415.

It is a super-3 number, since 3×51439620³ (a number of 24 digits) contains 333 as substring.

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

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, 1094437 + ... + 1094483.

It is an arithmetic number, because the mean of its divisors is an integer number (861840).

Almost surely, 2^51439620 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 51439620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82736640).

51439620 is an abundant number, since it is smaller than the sum of its proper divisors (114033660).

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

51439620 is a wasteful number, since it uses less digits than its factorization.

51439620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 51439620 is about 7172.1419394767. The cubic root of 51439620 is about 371.9054852959.

The spelling of 51439620 in words is "fifty-one million, four hundred thirty-nine thousand, six hundred twenty".