16778513401 has 4 divisors (see below), whose sum is σ = 18069168292. Its totient is φ = 15487858512.

The previous prime is 16778513393. The next prime is 16778513419. The reversal of 16778513401 is 10431587761.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3924396025 + 12854117376 = 62645^2 + 113376^2 .

It is a cyclic number.

It is not a de Polignac number, because 16778513401 - 2³ = 16778513393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16778513491) 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, 645327426 + ... + 645327451.

It is an arithmetic number, because the mean of its divisors is an integer number (4517292073).

Almost surely, 2^16778513401 is an apocalyptic number.

It is an amenable number.

16778513401 is a deficient number, since it is larger than the sum of its proper divisors (1290654891).

16778513401 is a wasteful number, since it uses less digits than its factorization.

16778513401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1290654890.

The product of its (nonzero) digits is 141120, while the sum is 43.

The spelling of 16778513401 in words is "sixteen billion, seven hundred seventy-eight million, five hundred thirteen thousand, four hundred one".