1399978406969 has 12 divisors (see below), whose sum is σ = 1486950677604. Its totient is φ = 1317847538592.

The previous prime is 1399978406941. The next prime is 1399978406971. The reversal of 1399978406969 is 9696048799931.

It can be written as a sum of positive squares in 2 ways, for example, as 196437763369 + 1203540643600 = 443213^2 + 1097060^2 .

It is not a de Polignac number, because 1399978406969 - 2¹² = 1399978402873 is a prime.

It is a super-2 number, since 2×1399978406969² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1399978406893 and 1399978406902.

It is not an unprimeable number, because it can be changed into a prime (1399978406909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12293822 + ... + 12407175.

It is an arithmetic number, because the mean of its divisors is an integer number (123912556467).

Almost surely, 2^{1399978406969} is an apocalyptic number.

1399978406969 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1399978406969 is a deficient number, since it is larger than the sum of its proper divisors (86972270635).

1399978406969 is a wasteful number, since it uses less digits than its factorization.

1399978406969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24701192 (or 24701173 counting only the distinct ones).

The product of its (nonzero) digits is 1428513408, while the sum is 80.

The spelling of 1399978406969 in words is "one trillion, three hundred ninety-nine billion, nine hundred seventy-eight million, four hundred six thousand, nine hundred sixty-nine".