256211421 has 16 divisors (see below), whose sum is σ = 366105984. Its totient is φ = 158963904.

The previous prime is 256211401. The next prime is 256211477. The reversal of 256211421 is 124112652.

It is not a de Polignac number, because 256211421 - 2⁶ = 256211357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256211391 and 256211400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256211401) 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, 47626 + ... + 52731.

It is an arithmetic number, because the mean of its divisors is an integer number (22881624).

Almost surely, 2^256211421 is an apocalyptic number.

It is an amenable number.

256211421 is a deficient number, since it is larger than the sum of its proper divisors (109894563).

256211421 is a wasteful number, since it uses less digits than its factorization.

256211421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100420.

The product of its digits is 960, while the sum is 24.

The square root of 256211421 is about 16006.6055427127. The cubic root of 256211421 is about 635.1351695221.

The spelling of 256211421 in words is "two hundred fifty-six million, two hundred eleven thousand, four hundred twenty-one".