51911000 has 128 divisors (see below), whose sum is σ = 132312960. Its totient is φ = 19008000.

The previous prime is 51910993. The next prime is 51911003. The reversal of 51911000 is 11915.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 51911000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51911003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 850970 + ... + 851030.

It is an arithmetic number, because the mean of its divisors is an integer number (1033695).

Almost surely, 2^51911000 is an apocalyptic number.

51911000 is a gapful number since it is divisible by the number (50) 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 51911000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66156480).

51911000 is an abundant number, since it is smaller than the sum of its proper divisors (80401960).

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

51911000 is a wasteful number, since it uses less digits than its factorization.

51911000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 128 counting only the distinct ones).

The product of its (nonzero) digits is 45, while the sum is 17.

The square root of 51911000 is about 7204.9288684900. The cubic root of 51911000 is about 373.0380495317.

Adding to 51911000 its reverse (11915), we get a palindrome (51922915).

The spelling of 51911000 in words is "fifty-one million, nine hundred eleven thousand".