216740731 has 2 divisors, whose sum is σ = 216740732. Its totient is φ = 216740730.

The previous prime is 216740681. The next prime is 216740749. The reversal of 216740731 is 137047612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216740731 - 2¹³ = 216732539 is a prime.

It is a super-2 number, since 2×216740731² = 93953088948828722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 216740693 and 216740702.

It is not a weakly prime, because it can be changed into another prime (216740761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108370365 + 108370366.

It is an arithmetic number, because the mean of its divisors is an integer number (108370366).

Almost surely, 2^216740731 is an apocalyptic number.

216740731 is a deficient number, since it is larger than the sum of its proper divisors (1).

216740731 is an equidigital number, since it uses as much as digits as its factorization.

216740731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 216740731 is about 14722.1170692262. The cubic root of 216740731 is about 600.6850795161.

The spelling of 216740731 in words is "two hundred sixteen million, seven hundred forty thousand, seven hundred thirty-one".