16601020621 has 16 divisors (see below), whose sum is σ = 17573776704. Its totient is φ = 15661344384.

The previous prime is 16601020607. The next prime is 16601020637. The reversal of 16601020621 is 12602010661.

It is a cyclic number.

It is not a de Polignac number, because 16601020621 - 2¹⁹ = 16600496333 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 (16601020691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 179886 + ... + 256048.

It is an arithmetic number, because the mean of its divisors is an integer number (1098361044).

Almost surely, 2^16601020621 is an apocalyptic number.

It is an amenable number.

16601020621 is a deficient number, since it is larger than the sum of its proper divisors (972756083).

16601020621 is a wasteful number, since it uses less digits than its factorization.

16601020621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76380.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 16601020621 in words is "sixteen billion, six hundred one million, twenty thousand, six hundred twenty-one".