1661472414721 has 16 divisors (see below), whose sum is σ = 1901929559040. Its totient is φ = 1421792035920.

The previous prime is 1661472414691. The next prime is 1661472414799. The reversal of 1661472414721 is 1274142741661.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1661472414721 - 2³⁹ = 1111716600833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661472418721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28407510 + ... + 28465936.

It is an arithmetic number, because the mean of its divisors is an integer number (118870597440).

Almost surely, 2^{1661472414721} is an apocalyptic number.

It is an amenable number.

1661472414721 is a deficient number, since it is larger than the sum of its proper divisors (240457144319).

1661472414721 is an equidigital number, since it uses as much as digits as its factorization.

1661472414721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65004.

The product of its digits is 451584, while the sum is 46.

The spelling of 1661472414721 in words is "one trillion, six hundred sixty-one billion, four hundred seventy-two million, four hundred fourteen thousand, seven hundred twenty-one".