511542640 has 80 divisors (see below), whose sum is σ = 1366573248. Its totient is φ = 174440448.

The previous prime is 511542637. The next prime is 511542641. The reversal of 511542640 is 46245115.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-3 number, since 3×511542640³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 511542599 and 511542608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (511542641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105714 + ... + 110446.

Almost surely, 2^511542640 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 511542640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (683286624).

511542640 is an abundant number, since it is smaller than the sum of its proper divisors (855030608).

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

511542640 is a wasteful number, since it uses less digits than its factorization.

511542640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4946 (or 4940 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 511542640 is about 22617.3084163434. The cubic root of 511542640 is about 799.7617207024.

Adding to 511542640 its reverse (46245115), we get a palindrome (557787755).

The spelling of 511542640 in words is "five hundred eleven million, five hundred forty-two thousand, six hundred forty".