683721017661 has 64 divisors (see below), whose sum is σ = 1051782036480. Its totient is φ = 390719946240.

The previous prime is 683721017633. The next prime is 683721017689. The reversal of 683721017661 is 166710127386.

It is an interprime number because it is at equal distance from previous prime (683721017633) and next prime (683721017689).

It is not a de Polignac number, because 683721017661 - 2¹³ = 683721009469 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 683721017661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (683721017611) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 151699770 + ... + 151704276.

It is an arithmetic number, because the mean of its divisors is an integer number (16434094320).

Almost surely, 2^683721017661 is an apocalyptic number.

It is an amenable number.

683721017661 is a deficient number, since it is larger than the sum of its proper divisors (368061018819).

683721017661 is a wasteful number, since it uses less digits than its factorization.

683721017661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5626.

The product of its (nonzero) digits is 508032, while the sum is 48.

The spelling of 683721017661 in words is "six hundred eighty-three billion, seven hundred twenty-one million, seventeen thousand, six hundred sixty-one".