51390612 has 216 divisors, whose sum is σ = 170797536. Its totient is φ = 13390272.

The previous prime is 51390587. The next prime is 51390617. The reversal of 51390612 is 21609315.

51390612 is a `hidden beast` number, since 513 + 90 + 61 + 2 = 666.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51390617) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 619123 + ... + 619205.

Almost surely, 2^51390612 is an apocalyptic number.

51390612 is a gapful number since it is divisible by the number (52) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51390612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85398768).

51390612 is an abundant number, since it is smaller than the sum of its proper divisors (119406924).

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

51390612 is a wasteful number, since it uses less digits than its factorization.

51390612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 51390612 is about 7168.7245727535. The cubic root of 51390612 is about 371.7873394300.

Adding to 51390612 its reverse (21609315), we get a palindrome (72999927).

It can be divided in two parts, 513 and 90612, that added together give a cube (91125 = 45³).

The spelling of 51390612 in words is "fifty-one million, three hundred ninety thousand, six hundred twelve".