216942131 has 4 divisors (see below), whose sum is σ = 247933872. Its totient is φ = 185950392.

The previous prime is 216942107. The next prime is 216942199. The reversal of 216942131 is 131249612.

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 216942131 - 2²² = 212747827 is a prime.

It is a super-2 number, since 2×216942131² = 94127776405642322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216942094 and 216942103.

It is not an unprimeable number, because it can be changed into a prime (216942101) 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, 15495860 + ... + 15495873.

It is an arithmetic number, because the mean of its divisors is an integer number (61983468).

Almost surely, 2^216942131 is an apocalyptic number.

216942131 is a deficient number, since it is larger than the sum of its proper divisors (30991741).

216942131 is an equidigital number, since it uses as much as digits as its factorization.

216942131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30991740.

The product of its digits is 2592, while the sum is 29.

The square root of 216942131 is about 14728.9555298399. The cubic root of 216942131 is about 600.8710782776.

The spelling of 216942131 in words is "two hundred sixteen million, nine hundred forty-two thousand, one hundred thirty-one".