16025397781 has 8 divisors (see below), whose sum is σ = 16273120664. Its totient is φ = 15778437120.

The previous prime is 16025397737. The next prime is 16025397793. The reversal of 16025397781 is 18779352061.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 11095251556 + 4930146225 = 105334^2 + 70215^2 .

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 16025397781 - 2⁷ = 16025397653 is a prime.

It is a super-2 number, since 2×16025397781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16025397481) 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, 148110 + ... + 232351.

It is an arithmetic number, because the mean of its divisors is an integer number (2034140083).

Almost surely, 2^16025397781 is an apocalyptic number.

It is an amenable number.

16025397781 is a deficient number, since it is larger than the sum of its proper divisors (247722883).

16025397781 is an equidigital number, since it uses as much as digits as its factorization.

16025397781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381111.

The product of its (nonzero) digits is 635040, while the sum is 49.

The spelling of 16025397781 in words is "sixteen billion, twenty-five million, three hundred ninety-seven thousand, seven hundred eighty-one".