53216681 has 16 divisors (see below), whose sum is σ = 64636416. Its totient is φ = 42771456.

The previous prime is 53216633. The next prime is 53216689. The reversal of 53216681 is 18661235.

53216681 = T₃₈₅ + T₃₈₆ + ... + T₇₂₁.

It is a happy number.

It is not a de Polignac number, because 53216681 - 2⁶ = 53216617 is a prime.

It is a super-2 number, since 2×53216681² = 5664030273311522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (53216689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39440 + ... + 40766.

It is an arithmetic number, because the mean of its divisors is an integer number (4039776).

Almost surely, 2^53216681 is an apocalyptic number.

It is an amenable number.

53216681 is a deficient number, since it is larger than the sum of its proper divisors (11419735).

53216681 is a wasteful number, since it uses less digits than its factorization.

53216681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688.

The product of its digits is 8640, while the sum is 32.

The square root of 53216681 is about 7294.9764221689. The cubic root of 53216681 is about 376.1397761033.

The spelling of 53216681 in words is "fifty-three million, two hundred sixteen thousand, six hundred eighty-one".