683356921 has 4 divisors (see below), whose sum is σ = 735922852. Its totient is φ = 630790992.

The previous prime is 683356913. The next prime is 683356951. The reversal of 683356921 is 129653386.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129653386 = 2 ⋅64826693.

It can be written as a sum of positive squares in 2 ways, for example, as 155276521 + 528080400 = 12461^2 + 22980^2 .

It is not a de Polignac number, because 683356921 - 2³ = 683356913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (683356951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26282946 + ... + 26282971.

It is an arithmetic number, because the mean of its divisors is an integer number (183980713).

Almost surely, 2^683356921 is an apocalyptic number.

It is an amenable number.

683356921 is a deficient number, since it is larger than the sum of its proper divisors (52565931).

683356921 is a wasteful number, since it uses less digits than its factorization.

683356921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52565930.

The product of its digits is 233280, while the sum is 43.

The square root of 683356921 is about 26141.0964001130. The cubic root of 683356921 is about 880.8105999469.

It can be divided in two parts, 683 and 356921, that added together give a square (357604 = 598²).

The spelling of 683356921 in words is "six hundred eighty-three million, three hundred fifty-six thousand, nine hundred twenty-one".