1661621341 has 8 divisors (see below), whose sum is σ = 1676314424. Its totient is φ = 1646991360.

The previous prime is 1661621333. The next prime is 1661621347. The reversal of 1661621341 is 1431261661.

It can be written as a sum of positive squares in 4 ways, for example, as 1058841 + 1660562500 = 1029^2 + 40750^2 .

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 1661621341 - 2³ = 1661621333 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 (1661621347) 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, 37921 + ... + 69001.

It is an arithmetic number, because the mean of its divisors is an integer number (209539303).

Almost surely, 2^1661621341 is an apocalyptic number.

It is an amenable number.

1661621341 is a deficient number, since it is larger than the sum of its proper divisors (14693083).

1661621341 is a wasteful number, since it uses less digits than its factorization.

1661621341 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31551.

The product of its digits is 5184, while the sum is 31.

The square root of 1661621341 is about 40762.9898437296. The cubic root of 1661621341 is about 1184.4335132324.

The spelling of 1661621341 in words is "one billion, six hundred sixty-one million, six hundred twenty-one thousand, three hundred forty-one".