681554 has 4 divisors (see below), whose sum is σ = 1022334. Its totient is φ = 340776.

The previous prime is 681539. The next prime is 681557. The reversal of 681554 is 455186.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 455186 = 2 ⋅227593.

It can be written as a sum of positive squares in only one way, i.e., 677329 + 4225 = 823^2 + 65^2 .

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (681557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170387 + ... + 170390.

2⁶⁸¹⁵⁵⁴ is an apocalyptic number.

681554 is a deficient number, since it is larger than the sum of its proper divisors (340780).

681554 is a wasteful number, since it uses less digits than its factorization.

681554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340779.

The product of its digits is 4800, while the sum is 29.

The square root of 681554 is about 825.5628383109. The cubic root of 681554 is about 88.0035294728.

The spelling of 681554 in words is "six hundred eighty-one thousand, five hundred fifty-four".