1661206015 has 8 divisors (see below), whose sum is σ = 2278225440. Its totient is φ = 1139112672.

The previous prime is 1661206013. The next prime is 1661206033. The reversal of 1661206015 is 5106021661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661206015 - 2¹ = 1661206013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661206013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23731480 + ... + 23731549.

It is an arithmetic number, because the mean of its divisors is an integer number (284778180).

Almost surely, 2^1661206015 is an apocalyptic number.

1661206015 is a deficient number, since it is larger than the sum of its proper divisors (617019425).

1661206015 is an equidigital number, since it uses as much as digits as its factorization.

1661206015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47463041.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 1661206015 is about 40757.8951247485. The cubic root of 1661206015 is about 1184.3348210670.

Adding to 1661206015 its reverse (5106021661), we get a palindrome (6767227676).

The spelling of 1661206015 in words is "one billion, six hundred sixty-one million, two hundred six thousand, fifteen".