1396804781 has 4 divisors (see below), whose sum is σ = 1397026464. Its totient is φ = 1396583100.

The previous prime is 1396804777. The next prime is 1396804859. The reversal of 1396804781 is 1874086931.

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: 1874086931 = 43 ⋅43583417.

It is a cyclic number.

It is not a de Polignac number, because 1396804781 - 2² = 1396804777 is a prime.

It is a super-2 number, since 2×1396804781² = 3902127192448915922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1396804751) 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, 101105 + ... + 114086.

It is an arithmetic number, because the mean of its divisors is an integer number (349256616).

Almost surely, 2^1396804781 is an apocalyptic number.

It is an amenable number.

1396804781 is a deficient number, since it is larger than the sum of its proper divisors (221683).

1396804781 is an equidigital number, since it uses as much as digits as its factorization.

1396804781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221682.

The product of its (nonzero) digits is 290304, while the sum is 47.

The square root of 1396804781 is about 37373.8515676402. The cubic root of 1396804781 is about 1117.8372328094.

The spelling of 1396804781 in words is "one billion, three hundred ninety-six million, eight hundred four thousand, seven hundred eighty-one".