57781000 has 32 divisors (see below), whose sum is σ = 135209880. Its totient is φ = 23112000.

The previous prime is 57780973. The next prime is 57781027. The reversal of 57781000 is 18775.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (57780973) and next prime (57781027).

It can be written as a sum of positive squares in 4 ways, for example, as 25948836 + 31832164 = 5094^2 + 5642^2 .

It is a super-2 number, since 2×57781000² = 6677287922000000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 57781000.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27891 + ... + 29890.

Almost surely, 2^57781000 is an apocalyptic number.

57781000 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

57781000 is an abundant number, since it is smaller than the sum of its proper divisors (77428880).

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

57781000 is a wasteful number, since it uses less digits than its factorization.

57781000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57802 (or 57788 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 28.

The square root of 57781000 is about 7601.3814533939. The cubic root of 57781000 is about 386.5998530349.

Adding to 57781000 its reverse (18775), we get a palindrome (57799775).

The spelling of 57781000 in words is "fifty-seven million, seven hundred eighty-one thousand".