1611021653 has 4 divisors (see below), whose sum is σ = 1611173568. Its totient is φ = 1610869740.

The previous prime is 1611021611. The next prime is 1611021673. The reversal of 1611021653 is 3561201161.

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: 3561201161 = 7 ⋅508743023.

It is a cyclic number.

It is not a de Polignac number, because 1611021653 - 2¹⁶ = 1610956117 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 (1611021673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58751 + ... + 81692.

It is an arithmetic number, because the mean of its divisors is an integer number (402793392).

Almost surely, 2^1611021653 is an apocalyptic number.

It is an amenable number.

1611021653 is a deficient number, since it is larger than the sum of its proper divisors (151915).

1611021653 is a wasteful number, since it uses less digits than its factorization.

1611021653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151914.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1611021653 is about 40137.5342167403. The cubic root of 1611021653 is about 1172.2865778427.

The spelling of 1611021653 in words is "one billion, six hundred eleven million, twenty-one thousand, six hundred fifty-three".