1404405661 has 4 divisors (see below), whose sum is σ = 1411061824. Its totient is φ = 1397749500.

The previous prime is 1404405641. The next prime is 1404405689. The reversal of 1404405661 is 1665044041.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1665044041 = 127 ⋅13110583.

It is a cyclic number.

It is not a de Polignac number, because 1404405661 - 2¹³ = 1404397469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1404405601) 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, 3327765 + ... + 3328186.

It is an arithmetic number, because the mean of its divisors is an integer number (352765456).

Almost surely, 2^1404405661 is an apocalyptic number.

It is an amenable number.

1404405661 is a deficient number, since it is larger than the sum of its proper divisors (6656163).

1404405661 is an equidigital number, since it uses as much as digits as its factorization.

1404405661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6656162.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 1404405661 is about 37475.4007450221. The cubic root of 1404405661 is about 1119.8611809771.

It can be divided in two parts, 140 and 4405661, that added together give a square (4405801 = 2099²).

The spelling of 1404405661 in words is "one billion, four hundred four million, four hundred five thousand, six hundred sixty-one".