16721525725 has 6 divisors (see below), whose sum is σ = 20734691930. Its totient is φ = 13377220560.

The previous prime is 16721525693. The next prime is 16721525747. The reversal of 16721525725 is 52752512761.

It can be written as a sum of positive squares in 3 ways, for example, as 2540764836 + 14180760889 = 50406^2 + 119083^2 .

It is not a de Polignac number, because 16721525725 - 2⁵ = 16721525693 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 334430490 + ... + 334430539.

Almost surely, 2^16721525725 is an apocalyptic number.

It is an amenable number.

16721525725 is a deficient number, since it is larger than the sum of its proper divisors (4013166205).

16721525725 is an equidigital number, since it uses as much as digits as its factorization.

16721525725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668861039 (or 668861034 counting only the distinct ones).

The product of its digits is 294000, while the sum is 43.

The spelling of 16721525725 in words is "sixteen billion, seven hundred twenty-one million, five hundred twenty-five thousand, seven hundred twenty-five".