16400621251 has 8 divisors (see below), whose sum is σ = 18751599360. Its totient is φ = 14051651208.

The previous prime is 16400621249. The next prime is 16400621261. The reversal of 16400621251 is 15212600461.

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

It is not a de Polignac number, because 16400621251 - 2¹ = 16400621249 is a prime.

It is a super-3 number, since 3×16400621251³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16400621261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 484471 + ... + 517216.

It is an arithmetic number, because the mean of its divisors is an integer number (2343949920).

Almost surely, 2^16400621251 is an apocalyptic number.

16400621251 is a deficient number, since it is larger than the sum of its proper divisors (2350978109).

16400621251 is a wasteful number, since it uses less digits than its factorization.

16400621251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1004033.

The product of its (nonzero) digits is 2880, while the sum is 28.

The spelling of 16400621251 in words is "sixteen billion, four hundred million, six hundred twenty-one thousand, two hundred fifty-one".