256651723340 has 48 divisors (see below), whose sum is σ = 562581718272. Its totient is φ = 98165808576.

The previous prime is 256651723301. The next prime is 256651723343. The reversal of 256651723340 is 43327156652.

It is a junction number, because it is equal to n+sod(n) for n = 256651723291 and 256651723300.

It is not an unprimeable number, because it can be changed into a prime (256651723343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1378487 + ... + 1553553.

It is an arithmetic number, because the mean of its divisors is an integer number (11720452464).

Almost surely, 2^256651723340 is an apocalyptic number.

256651723340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256651723340 is an abundant number, since it is smaller than the sum of its proper divisors (305929994932).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256651723340 is a wasteful number, since it uses less digits than its factorization.

256651723340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178286 (or 178284 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 44.

Adding to 256651723340 its reverse (43327156652), we get a palindrome (299978879992).

The spelling of 256651723340 in words is "two hundred fifty-six billion, six hundred fifty-one million, seven hundred twenty-three thousand, three hundred forty".