16721510401 has 4 divisors (see below), whose sum is σ = 16957024704. Its totient is φ = 16485996100.

The previous prime is 16721510363. The next prime is 16721510447. The reversal of 16721510401 is 10401512761.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10401512761 = 59627 ⋅174443.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16721510401 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16721510401.

It is not an unprimeable number, because it can be changed into a prime (16721513401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117757045 + ... + 117757186.

It is an arithmetic number, because the mean of its divisors is an integer number (4239256176).

It is a Proth number, since it is equal to 127575 ⋅ 2¹⁷ + 1 and 127575 < 2¹⁷.

Almost surely, 2^16721510401 is an apocalyptic number.

It is an amenable number.

16721510401 is a deficient number, since it is larger than the sum of its proper divisors (235514303).

16721510401 is an equidigital number, since it uses as much as digits as its factorization.

16721510401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235514302.

The product of its (nonzero) digits is 1680, while the sum is 28.

The spelling of 16721510401 in words is "sixteen billion, seven hundred twenty-one million, five hundred ten thousand, four hundred one".