1397044781 has 4 divisors (see below), whose sum is σ = 1524048864. Its totient is φ = 1270040700.

The previous prime is 1397044763. The next prime is 1397044799. The reversal of 1397044781 is 1874407931.

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.

It is an interprime number because it is at equal distance from previous prime (1397044763) and next prime (1397044799).

It is a cyclic number.

It is not a de Polignac number, because 1397044781 - 2²⁶ = 1329935917 is a prime.

It is a super-2 number, since 2×1397044781² = 3903468240238675922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1397044721) 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, 63502025 + ... + 63502046.

It is an arithmetic number, because the mean of its divisors is an integer number (381012216).

Almost surely, 2^1397044781 is an apocalyptic number.

1397044781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1397044781 is a deficient number, since it is larger than the sum of its proper divisors (127004083).

1397044781 is a wasteful number, since it uses less digits than its factorization.

1397044781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127004082.

The product of its (nonzero) digits is 169344, while the sum is 44.

The square root of 1397044781 is about 37377.0622307318. The cubic root of 1397044781 is about 1117.9012516749.

The spelling of 1397044781 in words is "one billion, three hundred ninety-seven million, forty-four thousand, seven hundred eighty-one".