1661231053 has 4 divisors (see below), whose sum is σ = 1666160860. Its totient is φ = 1656301248.

The previous prime is 1661231029. The next prime is 1661231059. The reversal of 1661231053 is 3501321661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3501321661 = 57943 ⋅60427.

It can be written as a sum of positive squares in 2 ways, for example, as 1118434249 + 542796804 = 33443^2 + 23298^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661231053 - 2⁹ = 1661230541 is a prime.

It is a super-2 number, since 2×1661231053² = 5519377222902977618, which contains 22 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 (1661231059) 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, 2464398 + ... + 2465071.

It is an arithmetic number, because the mean of its divisors is an integer number (416540215).

Almost surely, 2^1661231053 is an apocalyptic number.

It is an amenable number.

1661231053 is a deficient number, since it is larger than the sum of its proper divisors (4929807).

1661231053 is an equidigital number, since it uses as much as digits as its factorization.

1661231053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4929806.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 1661231053 is about 40758.2022788052. The cubic root of 1661231053 is about 1184.3407712072.

The spelling of 1661231053 in words is "one billion, six hundred sixty-one million, two hundred thirty-one thousand, fifty-three".