1621669539 has 8 divisors (see below), whose sum is σ = 2471115520. Its totient is φ = 926668296.

The previous prime is 1621669537. The next prime is 1621669547. The reversal of 1621669539 is 9359661261.

It is a happy number.

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

It is not a de Polignac number, because 1621669539 - 2¹ = 1621669537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621669537) 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, 38611159 + ... + 38611200.

It is an arithmetic number, because the mean of its divisors is an integer number (308889440).

Almost surely, 2^1621669539 is an apocalyptic number.

1621669539 is a deficient number, since it is larger than the sum of its proper divisors (849445981).

1621669539 is an equidigital number, since it uses as much as digits as its factorization.

1621669539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77222369.

The product of its digits is 524880, while the sum is 48.

The square root of 1621669539 is about 40269.9582691614. The cubic root of 1621669539 is about 1174.8636121157.

The spelling of 1621669539 in words is "one billion, six hundred twenty-one million, six hundred sixty-nine thousand, five hundred thirty-nine".