19780101 has 12 divisors (see below), whose sum is σ = 31168800. Its totient is φ = 11987880.

The previous prime is 19780093. The next prime is 19780109. The reversal of 19780101 is 10108791.

It is an interprime number because it is at equal distance from previous prime (19780093) and next prime (19780109).

It is not a de Polignac number, because 19780101 - 2³ = 19780093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19780109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 99801 + ... + 99998.

It is an arithmetic number, because the mean of its divisors is an integer number (2597400).

Almost surely, 2^19780101 is an apocalyptic number.

19780101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19780101 is a deficient number, since it is larger than the sum of its proper divisors (11388699).

19780101 is a wasteful number, since it uses less digits than its factorization.

19780101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199816 (or 199813 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 27.

The square root of 19780101 is about 4447.4825463401. The cubic root of 19780101 is about 270.4432636577.

Adding to 19780101 its reverse (10108791), we get a palindrome (29888892).

It can be divided in two parts, 19780 and 101, that added together give a square (19881 = 141²).

The spelling of 19780101 in words is "nineteen million, seven hundred eighty thousand, one hundred one".