403671661 has 4 divisors (see below), whose sum is σ = 403711900. Its totient is φ = 403631424.

The previous prime is 403671641. The next prime is 403671679. The reversal of 403671661 is 166176304.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 398002500 + 5669161 = 19950^2 + 2381^2 .

It is a cyclic number.

It is not a de Polignac number, because 403671661 - 2⁷ = 403671533 is a prime.

It is a super-3 number, since 3×403671661³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (403671641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8485 + ... + 29653.

It is an arithmetic number, because the mean of its divisors is an integer number (100927975).

Almost surely, 2^403671661 is an apocalyptic number.

It is an amenable number.

403671661 is a deficient number, since it is larger than the sum of its proper divisors (40239).

403671661 is a wasteful number, since it uses less digits than its factorization.

403671661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40238.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 403671661 is about 20091.5818441456. The cubic root of 403671661 is about 739.0538559340.

The spelling of 403671661 in words is "four hundred three million, six hundred seventy-one thousand, six hundred sixty-one".