216912881690 has 16 divisors (see below), whose sum is σ = 399966192360. Its totient is φ = 84648929280.

The previous prime is 216912881687. The next prime is 216912881701. The reversal of 216912881690 is 96188219612.

It can be written as a sum of positive squares in 4 ways, for example, as 50454593641 + 166458288049 = 224621^2 + 407993^2 .

It is a super-2 number, since 2×216912881690² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 264527495 + ... + 264528314.

Almost surely, 2^216912881690 is an apocalyptic number.

216912881690 is a deficient number, since it is larger than the sum of its proper divisors (183053310670).

216912881690 is a wasteful number, since it uses less digits than its factorization.

216912881690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529055857.

The product of its (nonzero) digits is 746496, while the sum is 53.

The spelling of 216912881690 in words is "two hundred sixteen billion, nine hundred twelve million, eight hundred eighty-one thousand, six hundred ninety".