511661000 has 64 divisors (see below), whose sum is σ = 1210950000. Its totient is φ = 202329600.

The previous prime is 511660997. The next prime is 511661011. The reversal of 511661000 is 166115.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 48636676 + 463024324 = 6974^2 + 21518^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86126 + ... + 91874.

Almost surely, 2^511661000 is an apocalyptic number.

511661000 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 511661000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (605475000).

511661000 is an abundant number, since it is smaller than the sum of its proper divisors (699289000).

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

511661000 is a wasteful number, since it uses less digits than its factorization.

511661000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5859 (or 5845 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 511661000 is about 22619.9248451448. The cubic root of 511661000 is about 799.8233985178.

The spelling of 511661000 in words is "five hundred eleven million, six hundred sixty-one thousand".