1397720026 has 8 divisors (see below), whose sum is σ = 2100457044. Its totient is φ = 697567680.

The previous prime is 1397720017. The next prime is 1397720041. The reversal of 1397720026 is 6200277931.

It can be written as a sum of positive squares in 2 ways, for example, as 1394947801 + 2772225 = 37349^2 + 1665^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 644815 + ... + 646978.

Almost surely, 2^1397720026 is an apocalyptic number.

1397720026 is a deficient number, since it is larger than the sum of its proper divisors (702737018).

1397720026 is a wasteful number, since it uses less digits than its factorization.

1397720026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1292336.

The product of its (nonzero) digits is 31752, while the sum is 37.

The square root of 1397720026 is about 37386.0940190333. The cubic root of 1397720026 is about 1118.0813307619.

Adding to 1397720026 its reverse (6200277931), we get a palindrome (7597997957).

The spelling of 1397720026 in words is "one billion, three hundred ninety-seven million, seven hundred twenty thousand, twenty-six".