251396947 has 4 divisors (see below), whose sum is σ = 251539416. Its totient is φ = 251254480.

The previous prime is 251396939. The next prime is 251396983. The reversal of 251396947 is 749693152.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 251396947 - 2³ = 251396939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 251396897 and 251396906.

It is not an unprimeable number, because it can be changed into a prime (251396917) 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, 68554 + ... + 72127.

It is an arithmetic number, because the mean of its divisors is an integer number (62884854).

Almost surely, 2^251396947 is an apocalyptic number.

251396947 is a deficient number, since it is larger than the sum of its proper divisors (142469).

251396947 is a wasteful number, since it uses less digits than its factorization.

251396947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142468.

The product of its digits is 408240, while the sum is 46.

The square root of 251396947 is about 15855.5021049477. The cubic root of 251396947 is about 631.1317081614.

The spelling of 251396947 in words is "two hundred fifty-one million, three hundred ninety-six thousand, nine hundred forty-seven".