213656421 has 16 divisors (see below), whose sum is σ = 311021568. Its totient is φ = 129385200.

The previous prime is 213656419. The next prime is 213656447. The reversal of 213656421 is 124656312.

213656421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 213656421 - 2¹ = 213656419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213656411) 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, 68130 + ... + 71196.

It is an arithmetic number, because the mean of its divisors is an integer number (19438848).

Almost surely, 2^213656421 is an apocalyptic number.

It is an amenable number.

213656421 is a deficient number, since it is larger than the sum of its proper divisors (97365147).

213656421 is a wasteful number, since it uses less digits than its factorization.

213656421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5192.

The product of its digits is 8640, while the sum is 30.

The square root of 213656421 is about 14616.9908325893. The cubic root of 213656421 is about 597.8221237678.

The spelling of 213656421 in words is "two hundred thirteen million, six hundred fifty-six thousand, four hundred twenty-one".