216461531 has 8 divisors (see below), whose sum is σ = 254304624. Its totient is φ = 181645920.

The previous prime is 216461513. The next prime is 216461627. The reversal of 216461531 is 135164612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216461531 - 2¹⁴ = 216445147 is a prime.

It is a super-2 number, since 2×216461531² = 93711188805727922, 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 = 216461494 and 216461503.

It is not an unprimeable number, because it can be changed into a prime (216461831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 756716 + ... + 757001.

It is an arithmetic number, because the mean of its divisors is an integer number (31788078).

Almost surely, 2^216461531 is an apocalyptic number.

216461531 is a deficient number, since it is larger than the sum of its proper divisors (37843093).

216461531 is a wasteful number, since it uses less digits than its factorization.

216461531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1513741.

The product of its digits is 4320, while the sum is 29.

The square root of 216461531 is about 14712.6316816537. The cubic root of 216461531 is about 600.4270395085.

The spelling of 216461531 in words is "two hundred sixteen million, four hundred sixty-one thousand, five hundred thirty-one".